Fix compile error in oss.c
Fix compile error in oss.c

Depending on the implementation of fileno(), it doesn't accept a void
pointer as its argument. This could make the compiler fail.

Reported by Hans Petter Selasky in tracker item 3587421.

uklauer/sox,pcqpcq/sox,CaptainHayashi/sox,Distrotech/sox,uklauer/sox,uklauer/sox,Distrotech/sox,davel/sox,pcqpcq/sox,CaptainHayashi/sox,cbagwell/sox,davel/sox,uklauer/sox,davel/sox,cbagwell/sox,pcqpcq/sox,davel/sox,pcqpcq/sox,Distrotech/sox,cbagwell/sox,CaptainHayashi/sox,Distrotech/sox,CaptainHayashi/sox,cbagwell/sox