build error check matches "INSTALL libavutil/error.h"

[DI FH Markus Kienast]

Eventhough the build of FFmpeg does succeed without errors, the way build-melted.sh checks for errors in the logs produces an error:

Line 991: grep -v "X Error" $TMPNAME | grep -i error 2>&1

The latter matches "INSTALL libavutil/error.h"

A patch can be found here: trickkiste@df8ecd8

[Brian Matherly]

Fixed in a7e79a3