smack: Always determine inode labels in smack_inode_init_security()

The inode_init_security hook is already a good place to initialize the
in-memory inode. And that is also what SELinux does.

In preparation for this, move the existing smack_inode_init_security() code
outside the 'if (xattr)' condition, and set the xattr, if provided.

This change does not have any impact on the current code, since every time
security_inode_init_security() is called, the initxattr() callback is
passed and, thus, xattr is non-NULL.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security/smack/smack_lsm.c

@@ -1000,7 +1000,6 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 	struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
 	int may;
 
-	if (xattr) {
 	/*
 	 * If equal, transmuting already occurred in
 	 * smack_dentry_create_files_as(). No need to check again.
@@ -1045,6 +1044,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 		}
 	}
 
+	if (xattr) {
 		xattr->value = kstrdup(isp->smk_known, GFP_NOFS);
 		if (!xattr->value)
 			return -ENOMEM;