xfs: Add attibute remove and helper functions

commit 068f985a9e5ec70fde58d8f679994fdbbd093a36 upstream.

This patch adds xfs_attr_remove_args. These sub-routines remove
the attributes specified in @args. We will use this later for setting
parent pointers as a deferred attribute operation.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>