New helper - current_umask()

current->fs->umask is what most of fs_struct users are doing.
Put that into a helper function.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 4c65a64..964c024 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1578,7 +1578,7 @@
 	struct dentry *dir = nd->path.dentry;
 
 	if (!IS_POSIXACL(dir->d_inode))
-		mode &= ~current->fs->umask;
+		mode &= ~current_umask();
 	error = security_path_mknod(&nd->path, path->dentry, mode, 0);
 	if (error)
 		goto out_unlock;
@@ -1989,7 +1989,7 @@
 		goto out_unlock;
 	}
 	if (!IS_POSIXACL(nd.path.dentry->d_inode))
-		mode &= ~current->fs->umask;
+		mode &= ~current_umask();
 	error = may_mknod(mode);
 	if (error)
 		goto out_dput;
@@ -2067,7 +2067,7 @@
 		goto out_unlock;
 
 	if (!IS_POSIXACL(nd.path.dentry->d_inode))
-		mode &= ~current->fs->umask;
+		mode &= ~current_umask();
 	error = mnt_want_write(nd.path.mnt);
 	if (error)
 		goto out_dput;