tests: trigger entry heals by lookup

Trigger entry heals explicitly by lookup until heal full is fixed in
afr v2 to do conservative merge.

Change-Id: I474b518045bebcf399bc414caff3b415259381d6
BUG: 1127148
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/8465
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com>