consitify do_mount() arguments

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 2874c73..38be92c 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -408,8 +408,8 @@
  * Returns 0 if current can write the floor of the filesystem
  * being mounted on, an error code otherwise.
  */
-static int smack_sb_mount(char *dev_name, struct path *path,
-			  char *type, unsigned long flags, void *data)
+static int smack_sb_mount(const char *dev_name, struct path *path,
+			  const char *type, unsigned long flags, void *data)
 {
 	struct superblock_smack *sbp = path->dentry->d_sb->s_security;
 	struct smk_audit_info ad;