parse: fix compiler warning
parse: fix compiler warning

Fix 'grammar.y:668: passing argument 1 of ‘g_free’ discards qualifiers
from pointer target type' compiler warning.

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