Remove one more set of useless parentheses from a return call.

Originally committed as revision 13070 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/vorbis_dec.c

@@ -169,7 +169,7 @@ static float vorbisfloat2float(uint_fast32_t val) {
     double mant=val&0x1fffff;
     long exp=(val&0x7fe00000L)>>21;
     if (val&0x80000000) mant=-mant;
-    return(ldexp(mant, exp-20-768));
+    return ldexp(mant, exp - 20 - 768);
 }