fix obvious coding error from yesterday's fix

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5369 65c4cc65-6c06-0410-ace0-fbb531ad65f3

logger.c

@@ -608,7 +608,7 @@ static void strip_coloring(char *str)
 {
 	char *src, *dest, *end;
 	
-	if (!src)
+	if (!str)
 		return;
 
 	/* find the first potential escape sequence in the string */