cluster/afr: Mem leak fixes found in valgrind for iozone

Change-Id: I869d191dc3470b2208c17343bbf772f01ef744cb
BUG: 1085511
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/7424
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>