CLEANUP: tools: typo in `strl2irc` mention

`str2irc` does not exist

Signed-off-by: William Dauchy <wdauchy@gmail.com>
diff --git a/src/tools.c b/src/tools.c
index 8fef15b..2d40d89 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -2178,7 +2178,7 @@
  * applications designed for hostile environments. It returns zero when the
  * number has successfully been converted, non-zero otherwise. When an error
  * is returned, the <ret> value is left untouched. It is about 3 times slower
- * than str2irc().
+ * than strl2irc().
  */
 
 int strl2llrc(const char *s, int len, long long *ret)