Add some parentheses to clarify operator precedence, fixes the warnings:

nut.c: In function 'ff_nut_sp_pos_cmp':
nut.c:43: warning: suggest parentheses around + or - inside shift
nut.c:43: warning: suggest parentheses around + or - inside shift
nut.c: In function 'ff_nut_sp_pts_cmp':
nut.c:47: warning: suggest parentheses around + or - inside shift
nut.c:47: warning: suggest parentheses around + or - inside shift

Originally committed as revision 10926 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/nut.c

@@ -40,11 +40,11 @@ int64_t ff_lsb2full(StreamContext *stream, int64_t lsb){
 }
 
 int ff_nut_sp_pos_cmp(syncpoint_t *a, syncpoint_t *b){
-    return (a->pos - b->pos>>32) - (b->pos - a->pos>>32);
+    return ((a->pos - b->pos) >> 32) - ((b->pos - a->pos) >> 32);
 }
 
 int ff_nut_sp_pts_cmp(syncpoint_t *a, syncpoint_t *b){
-    return (a->ts - b->ts>>32) - (b->ts - a->ts>>32);
+    return ((a->ts - b->ts) >> 32) - ((b->ts - a->ts) >> 32);
 }
 
 void ff_nut_add_sp(NUTContext *nut, int64_t pos, int64_t back_ptr, int64_t ts){