kconfig: util: Fix typo in comment

sting replaced with string

Signed-off-by: Thomas Weber <weber@corscience.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/scripts/kconfig/util.c b/scripts/kconfig/util.c
index b6b2a46a..25d1ec4 100644
--- a/scripts/kconfig/util.c
+++ b/scripts/kconfig/util.c
@@ -72,7 +72,7 @@
 }
 
 
-/* Allocate initial growable sting */
+/* Allocate initial growable string */
 struct gstr str_new(void)
 {
 	struct gstr gs;