protocol/server: '/s/ESTALE/ENOENT' only in lookup path

Problem:
[1] modified the server resolver code to send ENOENT instead of
ESTALE to older clients for all FOPS. This caused dht_mkdir
to fail under certain conditions (see bug description).

Fix:
Since [1] is needed by AFR only in its lookup path, reverted the changes
introduced by [1]  in resolve_entry_simple () an resolve_inode_simple () and
made the change instead in server_lookup_resume().

[1] http://review.gluster.org/#/c/8080

Change-Id: Idb2de25839fe712550486f2263a60c0531530d8f
BUG: 1118574
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/8294
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>