Fix a couple issues found when running ctest locally.

A couple issues cropped up when helping aviv debug ctest changes.
1) The --disk_layout change was never propagated to lib/test_helper
2) --only_verify without --quick should do the right thing.

This CL fixes both issues.

BUG=None
TEST=Ran it a few times with/without qemu image.

Change-Id: I072b8ef00aa08ac86e7a8d2677cd40fca3a0078c
Reviewed-on: https://gerrit.chromium.org/gerrit/64403
Tested-by: Chris Sosa <sosa@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Commit-Queue: Chris Sosa <sosa@chromium.org>
diff --git a/ctest/ctest.py b/ctest/ctest.py
index 403914b..0be81a8 100755
--- a/ctest/ctest.py
+++ b/ctest/ctest.py
@@ -178,11 +178,11 @@
     if suite:
       cmd.append('--verify_suite_name=%s' % suite)
 
-    if not full:
-      if only_verify:
-        cmd.append('--test_prefix=SimpleTestVerify')
-      else:
-        cmd.append('--test_prefix=SimpleTest')
+    # Only verify takes precedence over --quick.
+    if only_verify:
+      cmd.append('--test_prefix=SimpleTestVerify')
+    elif not full:
+      cmd.append('--test_prefix=SimpleTest')
 
     if self.test_results_root: cmd.append('--test_results_root=%s' %
                                           self.test_results_root)
diff --git a/lib/test_helper.py b/lib/test_helper.py
index 157a49a..508b903 100644
--- a/lib/test_helper.py
+++ b/lib/test_helper.py
@@ -58,7 +58,7 @@
            '--from=%s' % git.ReinterpretPathForChroot(os.path.dirname(image)),
            '--test_image']
     if full:
-      cmd.extend(['--full'])
+      cmd.extend(['--disk_layout', '2gb-rootfs-updatable'])
     if board:
       cmd.extend(['--board', board])