misc: get_system_type: RedHatEnterprise is RHEL
misc: get_system_type: RedHatEnterprise is RHEL

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@redhat.com>

ktdreyer/teuthology,ceph/teuthology,dmick/teuthology,dmick/teuthology,SUSE/teuthology,ceph/teuthology,dmick/teuthology,ktdreyer/teuthology,SUSE/teuthology,SUSE/teuthology