avcodec/bitstream: Dont try to free buffers for static VLCs

Such buffers are not malloced thus freeing would be bad.
Note though this condition never could have happened so this
is more for correctness sake and not a true bugfix

Fixes CID1061047
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/bitstream.c

@@ -304,13 +304,15 @@ int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
             continue;                                                       \
         if (buf[j].bits > 3*nb_bits || buf[j].bits>32) {                    \
             av_log(NULL, AV_LOG_ERROR, "Too long VLC (%d) in init_vlc\n", buf[j].bits);\
-            av_free(buf);                                                   \
+            if (!(flags & INIT_VLC_USE_NEW_STATIC))                         \
+                av_free(buf);                                               \
             return -1;                                                      \
         }                                                                   \
         GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size);            \
         if (buf[j].code >= (1LL<<buf[j].bits)) {                            \
             av_log(NULL, AV_LOG_ERROR, "Invalid code in init_vlc\n");       \
-            av_free(buf);                                                   \
+            if (!(flags & INIT_VLC_USE_NEW_STATIC))                         \
+                av_free(buf);                                               \
             return -1;                                                      \
         }                                                                   \
         if (flags & INIT_VLC_LE)                                            \