Fix SC2181 ("[ $?") outside tests/

Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12042

scripts/zloop.sh

@@ -62,11 +62,8 @@ function usage
 function or_die
 {
 	# shellcheck disable=SC2068
-	$@
-	# shellcheck disable=SC2181
-	if [[ $? -ne 0 ]]; then
-		# shellcheck disable=SC2145
-		echo "Command failed: $@"
+	if ! $@; then
+		echo "Command failed: $*"
 		exit 1
 	fi
 }