wma: Fix two gcc warnings on Slow Leopard:

Fixes

	wma_common.c: In function 'search_pattern':
	wma_common.c:41: warning: format '%u' expects type 'unsigned int', but argument 5 has type 'long int'
	wma_common.c: In function 'find_audio_stream_info':
	wma_common.c:59: warning: format '%0x' expects type 'unsigned int', but argument 4 has type 'long int'

The cast is neccessary because the type of a pointer difference is
implementation-defined...