FreeBSD: Parameterize ZFS_ENTER/ZFS_VERIFY_VP with an error code

For legacy reasons, a couple of VOPs have to return error numbers that
don't come from the usual errno namespace.  To handle the cases where
ZFS_ENTER or ZFS_VERIFY_ZP fail, we need to be able to override the
default error return value of EIO.  Extend the macros to permit this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes #13311

module/os/freebsd/zfs/zfs_vnops_os.c

@@ -5451,7 +5451,7 @@ zfs_getextattr(struct vop_getextattr_args *ap)
 
 	error = ENOENT;
 	ZFS_ENTER(zfsvfs);
-	ZFS_VERIFY_ZP(zp)
+	ZFS_VERIFY_ZP(zp);
 	rw_enter(&zp->z_xattr_lock, RW_READER);
 
 	error = zfs_getextattr_impl(ap, zfs_xattr_compat);