xfs: fix the errno sign for the xfs_errortag_{add,clearall} stubs

All errno values should be negative in the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Christoph Hellwig

fs/xfs/xfs_error.h

@@ -60,8 +60,8 @@ int xfs_errortag_clearall(struct xfs_mount *mp);
 #define xfs_errortag_del(mp)
 #define XFS_TEST_ERROR(mp, tag)			(false)
 #define XFS_ERRORTAG_DELAY(mp, tag)		((void)0)
-#define xfs_errortag_add(mp, tag)		(ENOSYS)
-#define xfs_errortag_clearall(mp)		(ENOSYS)
+#define xfs_errortag_add(mp, tag)		(-ENOSYS)
+#define xfs_errortag_clearall(mp)		(-ENOSYS)
 #endif /* DEBUG */
 
 /*