efivarfs: Drop link count of the right inode

efivarfs_unlink() should drop the file's link count, not the directory's.
Signed-off-by: Lingzhu Xiang <lxiang@redhat.com>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

drivers/firmware/efivars.c

@@ -994,7 +994,7 @@ static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
 		list_del(&var->list);
 		spin_unlock(&efivars->lock);
 		efivar_unregister(var);
-		drop_nlink(dir);
+		drop_nlink(dentry->d_inode);
 		dput(dentry);
 		return 0;
 	}