orangefs: clean up oversize xattr validation

Also don't check flags as this has been validated by the VFS already.

Fix an off-by-one error in the max size checking.

Stop logging just because userspace wants to write attributes which do
not fit.

This and the previous commit fix xfstests generic/020.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Marshall <hubcap@omnibond.com>