FS-11496: [core] fix crash with four channel sound file

src/switch_core_file.c

@@ -404,6 +404,7 @@ SWITCH_DECLARE(switch_status_t) switch_core_perform_file_open(const char *file,
 
 
 	if (fh->real_channels != fh->channels && (flags & SWITCH_FILE_FLAG_READ) && !(fh->flags & SWITCH_FILE_NOMUX)) {
+		fh->cur_channels = fh->real_channels;
 		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "File has %d channels, muxing to %d channel%s will occur.\n", fh->real_channels, fh->channels, fh->channels == 1 ? "" : "s");
 	}
 

src/switch_ivr_play_say.c

@@ -1664,7 +1664,7 @@ SWITCH_DECLARE(switch_status_t) switch_ivr_play_file(switch_core_session_t *sess
 				}
 			}
 
-			buflen = (FILE_STARTSAMPLES * sizeof(*abuf) * fh->cur_channels) > 0 ? fh->cur_channels : fh->channels;
+			buflen = FILE_STARTSAMPLES * sizeof(*abuf) * (fh->cur_channels > 0 ? fh->cur_channels : fh->channels); 
 
 			if (buflen > write_frame.buflen) {
 				abuf = realloc(abuf, buflen);