LU-1957 tests: remove sanity test 180 from ALWAYS_EXCEPT

LU-1957 tests: remove sanity test 180 from ALWAYS_EXCEPT

Remove test_180 from sanity ALWAYS_EXCEPT, since it should have been
fixed by landing LU-2803.

Lustre-change: https://review.whamcloud.com/35930
Lustre-commit: 72b59b85a253e508ec1b192fbf8cad840ca6ff2c

Fixes: e99f38594d2b ("LU-2803 osd: osd-zfs to handle echo sequence (2) properly")
Test-Parameters: trivial testlist=sanity fstype=zfs
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I7601164865baba8fe2db3ce7bb33fd4c81eb0291
Reviewed-by: James Nunez <jnunez@whamcloud.com>
Reviewed-by: Wei Liu <sarah@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/36930
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>