xfs: bulkstat should copy lastip whenever userspace supplies one

When userspace passes in a @lastip pointer we should copy the results
back, even if the @ocount pointer is NULL.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/xfs_ioctl.c

@@ -759,14 +759,13 @@ xfs_ioc_bulkstat(
 	if (error)
 		return error;
 
-	if (bulkreq.ocount != NULL) {
-		if (copy_to_user(bulkreq.lastip, &inlast,
-						sizeof(xfs_ino_t)))
-			return -EFAULT;
+	if (bulkreq.lastip != NULL &&
+	    copy_to_user(bulkreq.lastip, &inlast, sizeof(xfs_ino_t)))
+		return -EFAULT;
 
-		if (copy_to_user(bulkreq.ocount, &count, sizeof(count)))
-			return -EFAULT;
-	}
+	if (bulkreq.ocount != NULL &&
+	    copy_to_user(bulkreq.ocount, &count, sizeof(count)))
+		return -EFAULT;
 
 	return 0;
 }

fs/xfs/xfs_ioctl32.c

@@ -305,14 +305,13 @@ xfs_compat_ioc_bulkstat(
 	if (error)
 		return error;
 
-	if (bulkreq.ocount != NULL) {
-		if (copy_to_user(bulkreq.lastip, &inlast,
-						sizeof(xfs_ino_t)))
-			return -EFAULT;
+	if (bulkreq.lastip != NULL &&
+	    copy_to_user(bulkreq.lastip, &inlast, sizeof(xfs_ino_t)))
+		return -EFAULT;
 
-		if (copy_to_user(bulkreq.ocount, &count, sizeof(count)))
-			return -EFAULT;
-	}
+	if (bulkreq.ocount != NULL &&
+	    copy_to_user(bulkreq.ocount, &count, sizeof(count)))
+		return -EFAULT;
 
 	return 0;
 }