libx264: silence: warning: the address of val will always evaluate as true

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

libavcodec/libx264.c

@@ -237,7 +237,7 @@ static av_cold int X264_close(AVCodecContext *avctx)
 #define OPT_STR(opt, param)                                                   \
     do {                                                                      \
         int ret;                                                              \
-        if (param && (ret = x264_param_parse(&x4->params, opt, param)) < 0) { \
+        if (param!=NULL && (ret = x264_param_parse(&x4->params, opt, param)) < 0) { \
             if(ret == X264_PARAM_BAD_NAME)                                    \
                 av_log(avctx, AV_LOG_ERROR,                                   \
                         "bad option '%s': '%s'\n", opt, param);               \