ktest: Add TEST_TYPE install option

In testing one of my boxes, I found that I only wanted to build and
install the kernel. I wanted to manually reboot the box and test it.
Adding a TEST_TYPE option "install" allows this to happen.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/tools/testing/ktest/sample.conf b/tools/testing/ktest/sample.conf
index b8bcd14..eadca3e 100644
--- a/tools/testing/ktest/sample.conf
+++ b/tools/testing/ktest/sample.conf
@@ -253,9 +253,10 @@
 
 # The default test type (default test)
 # The test types may be:
-#   build - only build the kernel, do nothing else
-#   boot - build and boot the kernel
-#   test - build, boot and if TEST is set, run the test script
+#   build   - only build the kernel, do nothing else
+#   install - build and install, but do nothing else (does not reboot)
+#   boot    - build, install, and boot the kernel
+#   test    - build, boot and if TEST is set, run the test script
 #          (If TEST is not set, it defaults back to boot)
 #   bisect - Perform a bisect on the kernel (see BISECT_TYPE below)
 #   patchcheck - Do a test on a series of commits in git (see PATCHCHECK below)