Use [ -n "$x" ] in place of [ ! -z "$x" ] in chutney-git-bisect

Closes 29099.

scripts/test/chutney-git-bisect.sh

@@ -15,21 +15,21 @@
 # Skips the test if <skip-flavour> fails (default no skip).
 
 CHUTNEY_TRIES=3
-if [ ! -z "$1" ]; then
+if [ -n "$1" ]; then
     CHUTNEY_TRIES="$1"
 fi
 
-if [ ! -z "$2" ]; then
+if [ -n "$2" ]; then
     cd "$2" || exit
 fi
 
 CHUTNEY_TEST_CMD="make test-network-all"
-if [ ! -z "$3" ]; then
+if [ -n "$3" ]; then
     CHUTNEY_TEST_CMD="$CHUTNEY_PATH/tools/test-network.sh --flavour $3"
 fi
 
 CHUTNEY_SKIP_ON_FAIL_CMD="true"
-if [ ! -z "$4" ]; then
+if [ -n "$4" ]; then
     CHUTNEY_SKIP_ON_FAIL_CMD="$CHUTNEY_PATH/tools/test-network.sh --flavour $4"
 fi