consitify do_mount() arguments

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/capability.c b/security/capability.c
index a40aac6..b14a30c 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -74,8 +74,8 @@
 	return 0;
 }
 
-static int cap_sb_mount(char *dev_name, struct path *path, char *type,
-			unsigned long flags, void *data)
+static int cap_sb_mount(const char *dev_name, struct path *path,
+			const char *type, unsigned long flags, void *data)
 {
 	return 0;
 }