hack/bats: fix root/rootless logic

The ROOT{,LESS}_ONLY logic is confusing and unmaintainable.
Change it to an easier-to-read positive check.

Signed-off-by: Ed Santiago <santiago@redhat.com>

hack/bats

@@ -63,8 +63,8 @@ chcon -t container_runtime_exec_t $PODMAN
 TESTS=test/system
 
 REMOTE=
-ROOT_ONLY=
-ROOTLESS_ONLY=
+TEST_ROOT=1
+TEST_ROOTLESS=1
 
 declare -a bats_opts=()
 
@@ -74,8 +74,8 @@ for i;do
     value=`expr "$i" : '[^=]*=\(.*\)'`
     case "$i" in
         -h|--help)  echo "$usage"; exit 0;;
-        --root)     ROOT_ONLY=1 ;;
-        --rootless) ROOTLESS_ONLY=1 ;;
+        --root)     TEST_ROOTLESS= ;;
+        --rootless) TEST_ROOT= ;;
         --remote)   REMOTE=remote; echo "--remote is TBI"; exit 1;;
         --ts|-T)    bats_opts+=("-T") ;;
         */*.bats)   TESTS=$i ;;
@@ -106,7 +106,7 @@ fi
 export PODMAN_ROOTLESS_USER=$(id -un)
 
 # Root
-if [ -z "$ROOTLESS_ONLY" ]; then
+if [[ "$TEST_ROOT" ]]; then
     echo "# bats ${bats_filter[*]} $TESTS"
     sudo    --preserve-env=PODMAN \
             --preserve-env=QUADLET \
@@ -119,7 +119,7 @@ if [ -z "$ROOTLESS_ONLY" ]; then
 fi
 
 # Rootless. (Only if we're not already root)
-if [[ -z "$ROOT_ONLY" && "$(id -u)" != 0 ]]; then
+if [[ "$TEST_ROOTLESS" && "$(id -u)" != 0 ]]; then
     echo "--------------------------------------------------"
     echo "\$ bats ${bats_filter[*]} $TESTS"
     bats "${bats_opts[@]}" "${bats_filter[@]}" $TESTS