tgsi_to_nir: free disk cache value if the size is wrong

Fixes: 4db880d805 ("ttn: Implement disk cache")
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Rob Clark <robclark@freedesktop.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30308>

src/gallium/auxiliary/nir/tgsi_to_nir.c

@@ -2600,6 +2600,7 @@ load_nir_from_disk_cache(struct disk_cache *cache,
     * However we do still check if the first element is indeed the size,
     * as we cannot fully trust disk_cache_get (EGL_ANDROID_blob_cache) */
    if (buffer[0] != size) {
+      free(buffer);
       return NULL;
    }