get rid of open-coded S_ISREG(), etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/inode.c b/security/inode.c
index a67004f..bfe02e6 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -164,7 +164,7 @@
 	mutex_lock(&parent->d_inode->i_mutex);
 	*dentry = lookup_one_len(name, parent, strlen(name));
 	if (!IS_ERR(*dentry)) {
-		if ((mode & S_IFMT) == S_IFDIR)
+		if (S_ISDIR(mode))
 			error = mkdir(parent->d_inode, *dentry, mode);
 		else
 			error = create(parent->d_inode, *dentry, mode);