Merge commit '45acc228' into release/2.2

* commit '45acc228':
  doc: fix a couple of typos in frame.h

Conflicts:
	libavutil/frame.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/frame.h

@@ -596,7 +596,7 @@ AVFrame *av_frame_alloc(void);
 void av_frame_free(AVFrame **frame);
 
 /**
- * Setup a new reference to the data described by a given frame.
+ * Set up a new reference to the data described by the source frame.
  *
  * Copy frame properties from src to dst and create a new reference for each
  * AVBufferRef from src.