basesink: Fix typo in documentation
basesink: Fix typo in documentation

Fixes #652577.

krichter722/gstreamer,shelsonjava/gstreamer,jpakkane/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,drothlis/gstreamer,ylatuya/gstreamer,Distrotech/gstreamer,shelsonjava/gstreamer,lubosz/gstreamer,cablelabs/gstreamer,surround-io/gstreamer,collects/gstreamer,ylatuya/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,Lachann/gstreamer,surround-io/gstreamer,cablelabs/gstreamer,krieger-od/gstreamer,justinjoy/gstreamer,ahmedammar/platform_external_gst_gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,Distrotech/gstreamer,mparis/gstreamer,krieger-od/gstreamer,krichter722/gstreamer,lubosz/gstreamer,surround-io/gstreamer,krieger-od/gstreamer,cfoch/gstreamer,jpakkane/gstreamer,krieger-od/gstreamer,justinjoy/gstreamer,collects/gstreamer,collects/gstreamer,cablelabs/gstreamer,Lachann/gstreamer,Distrotech/gstreamer,Lachann/gstreamer,centricular/gstreamer,collects/gstreamer,centricular/gstreamer,drothlis/gstreamer,surround-io/gstreamer,Lachann/gstreamer,lubosz/gstreamer,drothlis/gstreamer,mparis/gstreamer,ylatuya/gstreamer,cablelabs/gstreamer,justinjoy/gstreamer,mparis/gstreamer,centricular/gstreamer,jpxiong/gstreamer,krieger-od/gstreamer,mparis/gstreamer,drothlis/gstreamer,Lachann/gstreamer,drothlis/gstreamer,magcius/gstreamer,collects/gstreamer,cfoch/gstreamer,ylatuya/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,cfoch/gstreamer,ahmedammar/platform_external_gst_gstreamer,shelsonjava/gstreamer,magcius/gstreamer,ensonic/gstreamer,cfoch/gstreamer,cablelabs/gstreamer,Distrotech/gstreamer,lubosz/gstreamer,ahmedammar/platform_external_gst_gstreamer,shelsonjava/gstreamer,cfoch/gstreamer,centricular/gstreamer,jpakkane/gstreamer,ensonic/gstreamer,magcius/gstreamer,ylatuya/gstreamer,lovebug356/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,ensonic/gstreamer,StreamUtils/gstreamer,magcius/gstreamer,justinjoy/gstreamer,centricular/gstreamer,justinjoy/gstreamer,ahmedammar/platform_external_gst_gstreamer,ahmedammar/platform_external_gst_gstreamer,lovebug356/gstreamer,lovebug356/gstreamer,magcius/gstreamer,krichter722/gstreamer,Distrotech/gstreamer,jpakkane/gstreamer,surround-io/gstreamer,lovebug356/gstreamer,lovebug356/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,mparis/gstreamer