patchtest/selftest: fix command arguments

Changes to patchtest's command-line arguments to work with oe-core by
default do not match the selftest script's argument list. Explicitly use
the --testdir and --repodir flags in selftest so that it is compatible
them.

(From OE-Core rev: 6cd547b24896596d4e0fe57f26f553842c5560b5)

Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/patchtest/selftest/selftest

@@ -37,7 +37,7 @@ def test(root, patch):
     res = True
     patchpath = os.path.abspath(os.path.join(root, patch))
     
-    cmd     = 'patchtest %s %s/tests --patch %s' % (repodir, topdir, patchpath)
+    cmd     = 'patchtest --repodir %s --testdir %s/tests --patch %s' % (repodir, topdir, patchpath)
     results = subprocess.check_output(cmd, stderr=subprocess.STDOUT, universal_newlines=True, shell=True)
 
     return results