huffyuvdec: swap code blocks

The effect is not really deterministic, as it seems to be a combination
on x86_64 of fewer registers used, different jump offsets and, for all
archs, of likely branches.

Speedup is around 15%.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/huffyuvdec.c

@@ -591,17 +591,17 @@ static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
         unsigned int index = SHOW_UBITS(name, gb, bits);            \
         int          code, n = dtable[index][1];                    \
                                                                     \
-        if (n>0) {                                                  \
-            code = dtable[index][0];                                \
-            OP(dst0, dst1, code);                                   \
-            LAST_SKIP_BITS(name, gb, n);                            \
-        } else {                                                    \
+        if (n<=0) {                                                 \
             int nb_bits;                                            \
             VLC_INTERN(dst0, table1, gb, name, bits, max_depth);    \
                                                                     \
             UPDATE_CACHE(re, gb);                                   \
             index = SHOW_UBITS(name, gb, bits);                     \
             VLC_INTERN(dst1, table2, gb, name, bits, max_depth);    \
+        } else {                                                    \
+            code = dtable[index][0];                                \
+            OP(dst0, dst1, code);                                   \
+            LAST_SKIP_BITS(name, gb, n);                            \
         }                                                           \
     } while (0)