selftests: vm: Update .gitignore with newly added tests

Update .gitignore with newly added tests.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/vm/.gitignore

@@ -8,3 +8,5 @@ on-fault-limit
 transhuge-stress
 userfaultfd
 mlock-intersect-test
+mlock-random-test
+virtual_address_range