Also add inttypes.h #include for PRId64 macros.

This fixes the following warnings:
libavformat/xwma.c:147: warning: too many arguments for format
libavformat/xwma.c:151: warning: too many arguments for format

Signed-off-by: Diego Biurrun <diego@biurrun.de>

ff_get_wav_header is reading data from a WAVE file and then uses it
(without validation) to malloc a buffer. It then proceeded to read
data into the buffer, without verifying that the allocation succeeded.

To address this, change ff_get_wav_header to return an error if
allocation failed, and adapted all calling code to handle that error.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>