LU-9054 tests: disable test_312 due to zdb issue

zdb used to work for datasets of exported pool by '-e -p' options,
this has been changed in zfs-0.7.0.

This patch temporarily disables test_312 until zfs upstream ticket
openzfs/zfs#6464 is solved.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: Ib0c9eeed4964ea4a0abfed70760cb8fbaeb44496
Reviewed-on: https://review.whamcloud.com/28343
Tested-by: Jenkins
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

lustre/tests/sanity.sh

@@ -12,8 +12,8 @@ ONLY=${ONLY:-"$*"}
 ALWAYS_EXCEPT="                42a    42b      42c     45   68b $SANITY_EXCEPT"
 # UPDATE THE COMMENT ABOVE WITH BUG NUMBERS WHEN CHANGING ALWAYS_EXCEPT!
 
-# bug number for skipped tests: LU-2036 LU-8411 LU-9096
-ALWAYS_EXCEPT="                 76	407     253 $ALWAYS_EXCEPT"
+# skipped tests: LU-2036 LU-8411 LU-9096 LU-9054
+ALWAYS_EXCEPT="  76	 407     253     312 $ALWAYS_EXCEPT"
 
 # Check Grants after these tests
 GRANT_CHECK_LIST="$GRANT_CHECK_LIST 42a 42b 42c 42d 42e 63a 63b 64a 64b 64c"