cmdutils&ffmpeg: use av_fopen_utf8() for passlogfile

might fix Ticket3056
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

cmdutils.c

@@ -1825,7 +1825,7 @@ int read_yesno(void)
 int cmdutils_read_file(const char *filename, char **bufptr, size_t *size)
 {
     int ret;
-    FILE *f = fopen(filename, "rb");
+    FILE *f = av_fopen_utf8(filename, "rb");
 
     if (!f) {
         av_log(NULL, AV_LOG_ERROR, "Cannot read file '%s': %s\n", filename,

ffmpeg.c

@@ -2468,7 +2468,7 @@ static int transcode_init(void)
                         codec->stats_in = logbuffer;
                     }
                     if (codec->flags & CODEC_FLAG_PASS1) {
-                        f = fopen(logfilename, "wb");
+                        f = av_fopen_utf8(logfilename, "wb");
                         if (!f) {
                             av_log(NULL, AV_LOG_FATAL, "Cannot write log file '%s' for pass-1 encoding: %s\n",
                                 logfilename, strerror(errno));