#8476 breaks in-tree tests

[c0d3z3r0]

System information

Type	Version/Name
Distribution Name	debian
Distribution Version	testing
Linux Kernel	not relevant
Architecture	amd64
ZFS Version	master
SPL Version	-

Describe the problem you're observing

Looks like the last change of #8476 - adding sudo - broke in-tree tests.

Describe how to reproduce the problem

$ ./scripts/zfs-tests.sh -xv -t tests/functional/cli_user/misc/dbufstat_001_pos

--- Cleanup ---
Removing pool(s):      
Removing dm(s):       
Removing loopback(s):  
Removing files(s):     

--- Configuration ---
Runfile:         /var/tmp/zfs-tests.28717.run
STF_TOOLS:       /usr/src/zfs/tests/test-runner
STF_SUITE:       /usr/src/zfs/tests/zfs-tests
STF_PATH:        /usr/src/zfs/bin
FILEDIR:         /var/tmp
FILES:           /var/tmp/file-vdev0 /var/tmp/file-vdev1 /var/tmp/file-vdev2
LOOPBACKS:       /dev/loop0 /dev/loop1 /dev/loop2 
DISKS:           loop0 loop1 loop2
NUM_DISKS:       3
FILESIZE:        4G
ITERATIONS:      1
TAGS:            functional
STACK_TRACER:    no
Keep pool(s):    rpool
Missing util(s): arp pax quotaon setenforce umask uuidgen wait 

/usr/src/zfs/tests/test-runner/bin/test-runner.py  -c /var/tmp/zfs-tests.28717.run -T functional -i /usr/src/zfs/tests/zfs-tests -I 1
Test: /usr/src/zfs/tests/zfs-tests/tests/functional/cli_user/misc/setup (run as root) [00:09] [PASS]
Test: /usr/src/zfs/tests/zfs-tests/tests/functional/cli_user/misc/dbufstat_001_pos (run as root) [00:00] [FAIL]
Test: /usr/src/zfs/tests/zfs-tests/tests/functional/cli_user/misc/cleanup (run as root) [00:01] [PASS]

Results Summary
PASS	   2
FAIL	   1

Running Time:	00:00:11
Percent passed:	66.7%
Log directory:	/var/tmp/test_results/20190802T185749

Tests with results other than PASS that are expected:

Tests with result of PASS that are unexpected:

Tests with results other than PASS that are unexpected:
    FAIL cli_user/misc/dbufstat_001_pos (expected PASS)

After reverting the sudo stuff in dbufstat_001_pos.ksh:

$ ./scripts/zfs-tests.sh -xv -t tests/functional/cli_user/misc/dbufstat_001_pos

--- Cleanup ---
Removing pool(s):      
Removing dm(s):       
Removing loopback(s):  
Removing files(s):     

--- Configuration ---
Runfile:         /var/tmp/zfs-tests.2930.run
STF_TOOLS:       /usr/src/zfs/tests/test-runner
STF_SUITE:       /usr/src/zfs/tests/zfs-tests
STF_PATH:        /usr/src/zfs/bin
FILEDIR:         /var/tmp
FILES:           /var/tmp/file-vdev0 /var/tmp/file-vdev1 /var/tmp/file-vdev2
LOOPBACKS:       /dev/loop0 /dev/loop1 /dev/loop2 
DISKS:           loop0 loop1 loop2
NUM_DISKS:       3
FILESIZE:        4G
ITERATIONS:      1
TAGS:            functional
STACK_TRACER:    no
Keep pool(s):    rpool
Missing util(s): arp pax quotaon setenforce umask uuidgen wait 

/usr/src/zfs/tests/test-runner/bin/test-runner.py  -c /var/tmp/zfs-tests.2930.run -T functional -i /usr/src/zfs/tests/zfs-tests -I 1
Test: /usr/src/zfs/tests/zfs-tests/tests/functional/cli_user/misc/setup (run as root) [00:10] [PASS]
Test: /usr/src/zfs/tests/zfs-tests/tests/functional/cli_user/misc/dbufstat_001_pos (run as root) [00:01] [PASS]
Test: /usr/src/zfs/tests/zfs-tests/tests/functional/cli_user/misc/cleanup (run as root) [00:01] [PASS]

Results Summary
PASS	   3

Running Time:	00:00:12
Percent passed:	100.0%
Log directory:	/var/tmp/test_results/20190802T190803

Tests with results other than PASS that are expected:

Tests with result of PASS that are unexpected:

Tests with results other than PASS that are unexpected:

Include any warning/errors/backtraces from the system logs

Stderr when failing:

ASSERTION: dbufstat generates output and doesn't return an error code
sudo: dbufstat: command not found
ERROR: eval sudo dbufstat  > /dev/null exited 1

[behlendorf]

@c0d3z3r0 PR #9196 has been opened with the proposed fix. Reviewers welcome.