vpxdec: report parse errors from webm_guess_framerate()
vpxdec: report parse errors from webm_guess_framerate()

If this function fails silently, the nestegg context is destroyed and
future nestegg calls will segfault.

Change-Id: Ie6a0ea284ab9ddfa97b1843ef8030a953937c8cd

reimaginemedia/webm.libvpx,enmasse-entertainment/libvpx,stewnorriss/libvpx,GrokImageCompression/aom,smarter/aom,Acidburn0zzz/webm.libvpx,charup/https---github.com-webmproject-libvpx-,pcwalton/libvpx,sanyaade-teachings/libvpx,iniwf/webm.libvpx,mwgoldsmith/libvpx,hsueceumd/test_hui,gshORTON/webm.libvpx,pcwalton/libvpx,turbulenz/libvpx,kalli123/webm.libvpx,ittiamvpx/libvpx,gshORTON/webm.libvpx,Distrotech/libvpx,cinema6/libvpx,genesi/libvpx0,turbulenz/libvpx,Suvarna1488/webm.libvpx,turbulenz/libvpx,altogother/webm.libvpx,luctrudeau/aom,WebRTC-Labs/libvpx,matanbs/vp982,running770/libvpx,shyamalschandra/libvpx,WebRTC-Labs/libvpx,jdm/libvpx,vasilvv/esvp8,reimaginemedia/webm.libvpx,sanyaade-teachings/libvpx,luctrudeau/aom,kalli123/webm.libvpx,ittiamvpx/libvpx-1,openpeer/libvpx_new,stewnorriss/libvpx,goodleixiao/vpx,n4t/libvpx,genesi/libvpx0,WebRTC-Labs/libvpx,gshORTON/webm.libvpx,reimaginemedia/webm.libvpx,openpeer/libvpx_new,mwgoldsmith/vpx,abwiz0086/webm.libvpx,mbebenita/aom,felipebetancur/libvpx,charup/https---github.com-webmproject-libvpx-,VTCSecureLLC/libvpx,gshORTON/webm.libvpx,matanbs/vp982,vasilvv/esvp8,running770/libvpx,jacklicn/webm.libvpx,matanbs/vp982,mwgoldsmith/vpx,lyx2014/libvpx_c,cinema6/libvpx,Maria1099/webm.libvpx,jdm/libvpx,jacklicn/webm.libvpx,enmasse-entertainment/libvpx,jdm/libvpx,gshORTON/webm.libvpx,shyamalschandra/libvpx,goodleixiao/vpx,kim42083/webm.libvpx,kalli123/webm.libvpx,reimaginemedia/webm.libvpx,Laknot/libvpx,mwgoldsmith/vpx,stewnorriss/libvpx,cinema6/libvpx,smarter/aom,WebRTC-Labs/libvpx,mbebenita/aom,mwgoldsmith/libvpx,kleopatra999/webm.libvpx,Acidburn0zzz/webm.libvpx,iniwf/webm.libvpx,Suvarna1488/webm.libvpx,enmasse-entertainment/libvpx,shareefalis/libvpx,thdav/aom,matanbs/webm.libvpx,matanbs/vp982,altogother/webm.libvpx,matanbs/webm.libvpx,rikaunite/gst-opera_libvpx,genesi/libvpx0,zofuthan/libvpx,felipebetancur/libvpx,Laknot/libvpx,Laknot/libvpx,shacklettbp/aom,liqianggao/libvpx,Laknot/libvpx,hsueceumd/test_hui,zofuthan/libvpx,mbebenita/aom,cinema6/libvpx,shacklettbp/aom,Distrotech/libvpx,zofuthan/libvpx,turbulenz/libvpx,luctrudeau/aom,shyamalschandra/libvpx,WebRTC-Labs/libvpx,enmasse-entertainment/libvpx,running770/libvpx,luctrudeau/aom,Distrotech/libvpx,ShiftMediaProject/libvpx,Suvarna1488/webm.libvpx,felipebetancur/libvpx,cinema6/libvpx,felipebetancur/libvpx,Acidburn0zzz/webm.libvpx,kleopatra999/webm.libvpx,thdav/aom,mbebenita/aom,ittiamvpx/libvpx,shareefalis/libvpx,ittiamvpx/libvpx-1,charup/https---github.com-webmproject-libvpx-,felipebetancur/libvpx,cinema6/libvpx,kim42083/webm.libvpx,altogother/webm.libvpx,mwgoldsmith/vpx,Maria1099/webm.libvpx,jmvalin/aom,zofuthan/libvpx,mwgoldsmith/libvpx,jmvalin/aom,shacklettbp/aom,webmproject/libvpx,webmproject/libvpx,mbebenita/aom,liqianggao/libvpx,n4t/libvpx,sanyaade-teachings/libvpx,ShiftMediaProject/libvpx,charup/https---github.com-webmproject-libvpx-,webmproject/libvpx,liqianggao/libvpx,mbebenita/aom,shacklettbp/aom,GrokImageCompression/aom,ShiftMediaProject/libvpx,smarter/aom,charup/https---github.com-webmproject-libvpx-,genesi/libvpx0,vasilvv/esvp8,genesi/libvpx0,VTCSecureLLC/libvpx,reimaginemedia/webm.libvpx,goodleixiao/vpx,stewnorriss/libvpx,shyamalschandra/libvpx,goodleixiao/vpx,openpeer/libvpx_new,altogother/webm.libvpx,kleopatra999/webm.libvpx,lyx2014/libvpx_c,n4t/libvpx,mbebenita/aom,kleopatra999/webm.libvpx,kalli123/webm.libvpx,Maria1099/webm.libvpx,VTCSecureLLC/libvpx,Topopiccione/libvpx,jacklicn/webm.libvpx,rikaunite/gst-opera_libvpx,ShiftMediaProject/libvpx,matanbs/webm.libvpx,turbulenz/libvpx,abwiz0086/webm.libvpx,iniwf/webm.libvpx,kalli123/webm.libvpx,GrokImageCompression/aom,hsueceumd/test_hui,running770/libvpx,jdm/libvpx,vasilvv/esvp8,thdav/aom,felipebetancur/libvpx,Acidburn0zzz/webm.libvpx,vasilvv/esvp8,ittiamvpx/libvpx,turbulenz/libvpx,iniwf/webm.libvpx,liqianggao/libvpx,abwiz0086/webm.libvpx,mwgoldsmith/vpx,kim42083/webm.libvpx,ittiamvpx/libvpx,turbulenz/libvpx,zofuthan/libvpx,pcwalton/libvpx,matanbs/vp982,kim42083/webm.libvpx,running770/libvpx,altogother/webm.libvpx,turbulenz/libvpx,mwgoldsmith/vpx,Suvarna1488/webm.libvpx,jmvalin/aom,openpeer/libvpx_new,Maria1099/webm.libvpx,Acidburn0zzz/webm.libvpx,GrokImageCompression/aom,vasilvv/esvp8,kim42083/webm.libvpx,liqianggao/libvpx,kim42083/webm.libvpx,ittiamvpx/libvpx-1,mwgoldsmith/libvpx,rikaunite/gst-opera_libvpx,webmproject/libvpx,awatry/libvpx.opencl,Laknot/libvpx,genesi/libvpx0,matanbs/vp982,stewnorriss/libvpx,thdav/aom,reimaginemedia/webm.libvpx,altogother/webm.libvpx,n4t/libvpx,jmvalin/aom,goodleixiao/vpx,ShiftMediaProject/libvpx,awatry/libvpx.opencl,webmproject/libvpx,mwgoldsmith/libvpx,pcwalton/libvpx,Distrotech/libvpx,webmproject/libvpx,ittiamvpx/libvpx-1,goodleixiao/vpx,Topopiccione/libvpx,ittiamvpx/libvpx,kalli123/webm.libvpx,Topopiccione/libvpx,shyamalschandra/libvpx,ittiamvpx/libvpx,jacklicn/webm.libvpx,vasilvv/esvp8,cinema6/libvpx,shacklettbp/aom,lyx2014/libvpx_c,shareefalis/libvpx,Maria1099/webm.libvpx,lyx2014/libvpx_c,abwiz0086/webm.libvpx,iniwf/web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