LU-9767 utils: validate filesystem name for mkfs.lustre

LU-9767 utils: validate filesystem name for mkfs.lustre

In an earlier LU-6401 patch various user land functions
used to validate poolnames and file system names were
removed. The checks instead were enforced on the kernel
side to ensure any possible user land software directly
interfacing to the kernel wouldn't be able to break
things badly. For the case of formating the backend
file system no kernel interaction doesn't happen until
it tries to mount the MDT/OST/MGT which is very late
in the process. So for this case lets add back the
file system name verification to mkfs.lustre to warn
users long before they try to mount anything.

Secondly we remove the verify_poolname() in lfs.c since
it really doesn't do much.

Test-Parameters: trivial

Lustre-commit: 28216a73f4c0b19ef45e3ec2d6949801f6b9f828
Lustre-change: https://review.whamcloud.com/28070

Change-Id: If094644e56a70b6dd8e6b0378adc8736911aeef1
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/28070
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: https://review.whamcloud.com/28996
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>