NFSv3 - don't return garbage after setattr

If setattr was only changing size then the attributes
are invalid and cannot be used to populate wcc replay.

Ported from 1.5.x:  4a3af6df1b46075b80f33e43e3f19fd768e6c43a

Signed-off-by: Max Matveev <makc@gmx.co.uk>
Signed-off-by: Venkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>
Merge branch 'tp/jv27-ports' into ibm_next_20_tmp
Merge branch 'tp/rz_dev33_0515' into ibm_next_20_tmp
Merge branch 'tp/jv-pre-2.0-dev_33_2' into ibm_next_20_tmp