LU-13701 tests: stop running sanity-lnet tests

LU-13701 tests: stop running sanity-lnet tests

sanity-lnet tests 204, 205, 206, 207 and 208 are failing at
a very high rate for ARM client testing.  We need to stop
running these tests, add them to the ALWAYS_EXCEPT list,
until we understand why these tests are failing.

Test-Parameters: trivial testgroup=review-ldiskfs-arm
Signed-off-by: James Nunez <jnunez@whamcloud.com>
Change-Id: Ia3e970748d719f25b156666a0b37ac9d89535532
Reviewed-on: https://review.whamcloud.com/39155
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>