tests: get rid of which

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13259

tests/zfs-tests/include/commands.cfg

@@ -109,8 +109,7 @@ export SYSTEM_FILES_COMMON='arp
     uuidgen
     vmstat
     wait
-    wc
-    which'
+    wc'
 
 export SYSTEM_FILES_FREEBSD='chflags
     compress

tests/zfs-tests/include/libtest.shlib

@@ -2618,7 +2618,7 @@ function add_user_linux #<group_name> <user_name> <basedir>
 	# Add new users to the same group and the command line utils.
 	# This allows them to be run out of the original users home
 	# directory as long as it permissioned to be group readable.
-	cmd_group=$(stat --format="%G" $(which zfs))
+	cmd_group=$(stat --format="%G" $(command -v zfs))
 	log_must usermod -a -G $cmd_group $user
 
 	return 0

tests/zfs-tests/tests/functional/mmap/mmap_libaio_001_pos.ksh

@@ -42,9 +42,7 @@ verify_runnable "global"
 log_assert "verify mmap'd pages work with libaio"
 
 # mmap_libaio is built when the libaio-devel package is installed.
-if ! which mmap_libaio; then
-	log_unsupported "This test requires mmap_libaio."
-fi
+command -v mmap_libaio > /dev/null || log_unsupported "This test requires mmap_libaio."
 
 log_must chmod 777 $TESTDIR
 

tests/zfs-tests/tests/functional/pam/setup.ksh

@@ -22,9 +22,7 @@
 
 . $STF_SUITE/tests/functional/pam/utilities.kshlib
 
-if ! which pamtester; then
-        log_unsupported "pam tests require the pamtester utility to be installed"
-fi
+command -v pamtester > /dev/null || log_unsupported "pam tests require the pamtester utility to be installed"
 
 DISK=${DISKS%% *}
 create_pool $TESTPOOL "$DISK"

tests/zfs-tests/tests/functional/user_namespace/user_namespace_001.ksh

@@ -51,8 +51,8 @@ log_onexit cleanup
 
 log_assert "Check root in user namespaces"
 
-TOUCH=$(readlink -e $(which touch))
-CHMOD=$(readlink -e $(which chmod))
+TOUCH=$(readlink -f $(command -v touch))
+CHMOD=$(readlink -f $(command -v chmod))
 
 for i in ${files[*]}; do
 	log_must $TOUCH $TESTDIR/$i