extended: Allow to focus on particular tests

Focus usually involves string with spaces such as:

    ./test/extended/core.sh --ginkgo.focus='quota admission' --ginkgo.failFast

Signed-off-by: Michal Minar <miminar@redhat.com>

test/extended/core.sh

@@ -12,7 +12,7 @@ source "${OS_ROOT}/test/extended/setup.sh"
 cd "${OS_ROOT}"
 
 os::test::extended::setup
-os::test::extended::focus $@
+os::test::extended::focus "$@"
 
 function join { local IFS="$1"; shift; echo "$*"; }
 
@@ -43,4 +43,4 @@ TEST_REPORT_FILE_NAME=core_parallel ${GINKGO} -v "-focus=${pf}" "-skip=${ps}" -p
 echo "[INFO] Running serial tests"
 TEST_REPORT_FILE_NAME=core_serial ${GINKGO} -v "-focus=${sf}" "-skip=${ss}" ${EXTENDEDTEST} -- -ginkgo.v -test.timeout 2h || exitstatus=$?
 
-exit $exitstatus
+exit $exitstatus