Rectify the guard macro name of glusterfs-acl.h

Change-Id: I13bc7626c7f852647a75e3d5e397d2cd55757932
BUG: 1009210
Signed-off-by: Santosh Kumar Pradhan <spradhan@redhat.com>
Reviewed-on: http://review.gluster.org/6117
Reviewed-by: Anand Avati <avati@redhat.com>
Tested-by: Anand Avati <avati@redhat.com>