LU-16309 tests: skip test_150b() for EOPNOTSUPP

LU-16309 tests: skip test_150b() for EOPNOTSUPP

Fix sanity:test_150b() to really be skipped if
check_fallocate returs EOPNOTSUPP.

Fixes: 2f496148c3 ("LU-15551 ofd: Return EOPNOTSUPP instead of EPROTO")
Test-Parameters: trivial testlist="sanity" env=ONLY="150b"
Signed-off-by: Elena Gryaznova <elena.gryaznova@hpe.com>
HPE-bug-id: LUS-10961
Reviewed-by: Vladimir Saveliev <vladimir.saveliev@hpe.com>
Change-Id: I253b89bb3dd047434c7fa0e91bb0faefef24e128
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49136
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>