LU-6950 utils: support SELinux context labelling

LU-6950 utils: support SELinux context labelling

SELinux contexts are applied by the kernel if mount options are
not binary. As we don't use any binary mount options in Lustre,
remove the binary mount option flag.

Signed-off-by: Andrew Wellington <andrew.wellington@anu.edu.au>
Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I363886f58939c1f7384de2ff579968a19f1460bc
Reviewed-on: http://review.whamcloud.com/15840
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Sebastien Buisson <sebastien.buisson@bull.net>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>