sanitize cifs_umount() prototype

a) superblock argument is unused
b) it always returns 0

Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/cifs/cifsfs.c

@@ -172,7 +172,7 @@ out_no_root:
 	if (inode)
 		iput(inode);
 
-	cifs_umount(sb, cifs_sb);
+	cifs_umount(cifs_sb);
 	return rc;
 }
 
@@ -189,9 +189,7 @@ cifs_put_super(struct super_block *sb)
 		return;
 	}
 
-	rc = cifs_umount(sb, cifs_sb);
-	if (rc)
-		cERROR(1, "cifs_umount failed with return code %d", rc);
+	cifs_umount(cifs_sb);
 }
 
 static void cifs_kill_sb(struct super_block *sb)

fs/cifs/cifsproto.h

@@ -158,7 +158,7 @@ extern void cifs_cleanup_volume_info(struct smb_vol **pvolume_info);
 extern int cifs_setup_volume_info(struct smb_vol **pvolume_info,
 				  char *mount_data, const char *devname);
 extern int cifs_mount(struct cifs_sb_info *, struct smb_vol *);
-extern int cifs_umount(struct super_block *, struct cifs_sb_info *);
+extern void cifs_umount(struct cifs_sb_info *);
 extern void cifs_dfs_release_automount_timer(void);
 void cifs_proc_init(void);
 void cifs_proc_clean(void);

fs/cifs/connect.c

@@ -3339,8 +3339,8 @@ CIFSTCon(unsigned int xid, struct cifs_ses *ses,
 	return rc;
 }
 
-int
-cifs_umount(struct super_block *sb, struct cifs_sb_info *cifs_sb)
+void
+cifs_umount(struct cifs_sb_info *cifs_sb)
 {
 	struct rb_root *root = &cifs_sb->tlink_tree;
 	struct rb_node *node;
@@ -3362,7 +3362,6 @@ cifs_umount(struct super_block *sb, struct cifs_sb_info *cifs_sb)
 	spin_unlock(&cifs_sb->tlink_tree_lock);
 
 	bdi_destroy(&cifs_sb->bdi);
-	return 0;
 }
 
 int cifs_negotiate_protocol(unsigned int xid, struct cifs_ses *ses)