OS-1571 Placate gcc -Wparentheses
Reviewed by: Robert Mustacchi <rm@joyent.com>

@@ -272,12 +272,13 @@
         mutex_exit(&mvp->v_lock);
 
         /* Having the resource be anything but "swap" doesn't make sense. */
         vfs_setresource(vfsp, "swap", 0);
 
-        if (error = pn_get(uap->dir,
-            (uap->flags & MS_SYSSPACE) ? UIO_SYSSPACE : UIO_USERSPACE, &dpn))
+        if ((error = pn_get(uap->dir,
+            (uap->flags & MS_SYSSPACE) ? UIO_SYSSPACE : UIO_USERSPACE,
+            &dpn)) != 0)
                 goto out;
 
         if ((hm = hyprlofs_memalloc(sizeof (hlfsmount_t), 0)) == NULL) {
                 pn_free(&dpn);
                 error = ENOMEM;