Check more completely for invalid pix_fmts in planarRgb16ToRgb16Wrapper()

This makes the conversion function more robust.

libswscale/swscale_unscaled.c

@@ -495,7 +495,8 @@ static int planarRgb16ToRgb16Wrapper(SwsContext *c, const uint8_t *src[],
         swap += 2;
 
     if ((src_format->flags & (AV_PIX_FMT_FLAG_PLANAR | AV_PIX_FMT_FLAG_RGB)) !=
-        (AV_PIX_FMT_FLAG_PLANAR | AV_PIX_FMT_FLAG_RGB)) {
+        (AV_PIX_FMT_FLAG_PLANAR | AV_PIX_FMT_FLAG_RGB) ||
+        bits_per_sample <= 8) {
         av_log(c, AV_LOG_ERROR, "unsupported planar RGB conversion %s -> %s\n",
                src_format->name, dst_format->name);
         return srcSliceH;