Bug#632303: Diff to enable OSS4

[Steven McDonald]

Hello,

I am a user of kFreeBSD. I have tested audacious-plugins without this
patch, and the old OSS plugin works just fine with kFreeBSD's OSS
implementation. However, it does not build with --enable-oss4:

utils.c: In function ‘oss_format_to_text’:
utils.c:33:10: error: ‘AFMT_FLOAT’ undeclared (first use in this function)
utils.c:33:10: note: each undeclared identifier is reported only once for each function it appears in
utils.c: In function ‘oss_convert_aud_format’:
utils.c:68:22: error: ‘AFMT_FLOAT’ undeclared (first use in this function)
utils.c:68:9: warning: initialization makes integer from pointer without a cast [enabled by default]
utils.c:68:9: warning: (near initialization for ‘table[0].format’) [enabled by default]
utils.c: In function ‘oss_format_to_bits’:
utils.c:116:14: error: ‘AFMT_FLOAT’ undeclared (first use in this function)

I wouldn't consider this to be worthwhile fixing unless somebody really
wants to use OSSv4 on kFreeBSD, as the FreeBSD OSS implementation is
far better in my opinion. Please only enable the OSSv4 output plugin on
Linux.