Fix breakage in shmem.c

Replacing
	error = 0;
	if (error)
		op
with nothing is not quite an equivalent transformation ;-)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

mm/shmem.c

@@ -1830,6 +1830,8 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 			iput(inode);
 			return error;
 		}
+#else
+		error = 0;
 #endif
 		if (dir->i_mode & S_ISGID) {
 			inode->i_gid = dir->i_gid;