ext/amrnb/amrnbenc.c: The AMR encoder writes into the audio buffers it processes...

ext/amrnb/amrnbenc.c: The AMR encoder writes into the audio buffers it processes, so use gst_buffer_make_writable() o...

Original commit message from CVS:
* ext/amrnb/amrnbenc.c: (gst_amrnbenc_chain):
The AMR encoder writes into the audio buffers it processes, so
use gst_buffer_make_writable() on buffers we might (they go through
an adapter, so there can be copying going on later anyway) be
encoding.