ZTS: add snapshot/snapshot_002_pos exception

Add snapshot_002_pos to the known list of occasional failures
for FreeBSD until it can be made entirely reliable.

Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #14831
Closes #14832

tests/test-runner/bin/zts-report.py.in

@@ -257,6 +257,7 @@ if sys.platform.startswith('freebsd'):
         'resilver/resilver_restart_001': ['FAIL', known_reason],
         'pool_checkpoint/checkpoint_big_rewind': ['FAIL', 12622],
         'pool_checkpoint/checkpoint_indirect': ['FAIL', 12623],
+        'snapshot/snapshot_002_pos': ['FAIL', '14831'],
     })
 elif sys.platform.startswith('linux'):
     maybe.update({