LU-8705 tests: do not skip lnet-selftest for DNE

LU-8705 tests: do not skip lnet-selftest for DNE

Patch removes the skip added by LU-4181.

Test-Parameters: mdtfilesystemtype=ldiskfs mdsfilesystemtype=ldiskfs ostfilesystemtype=ldiskfs mdscount=2 mdtcount=4 testlist=lnet-selftest
Seagate-bug-id: MRP-3912
Signed-off-by: Elena Gryaznova <elena.gryaznova@seagate.com>
Reviewed-by: Vladimir Saveliev <vladimir.saveliev@seagate.com>
Reviewed-by: Alexander Lezhoev <alexander.lezhoev@seagate.com>
Tested-by: Alexander Lezhoev <alexander.lezhoev@seagate.com>
Change-Id: Id78ef3909896325d55569ea948f75906cf0b7c87
Reviewed-on: http://review.whamcloud.com/23138
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>