avcodec/hevcdec: hevc_await_progress: declare |y| only if used.

hevc_await_progress() uses the variable |y| only inside the "if" block.
So |y| only needs to be declared and initialized in that block.
Signed-off-by: Wan-Teh Chang <wtc@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/hevcdec.c

@@ -1684,10 +1684,11 @@ static void chroma_mc_bi(HEVCContext *s, uint8_t *dst0, ptrdiff_t dststride, AVF
 static void hevc_await_progress(HEVCContext *s, HEVCFrame *ref,
                                 const Mv *mv, int y0, int height)
 {
-    int y = FFMAX(0, (mv->y >> 2) + y0 + height + 9);
+    if (s->threads_type == FF_THREAD_FRAME ) {
+        int y = FFMAX(0, (mv->y >> 2) + y0 + height + 9);
 
-    if (s->threads_type == FF_THREAD_FRAME )
         ff_thread_await_progress(&ref->tf, y, 0);
+    }
 }
 
 static void hevc_luma_mv_mvp_mode(HEVCContext *s, int x0, int y0, int nPbW,