test: Move stat-printing into its own function

Add a function to show the stats, so we can decide when to print it.

This slightly adjusts the output, so that any 'test not found' message
appears on its own line after all other output.

The 'failures' message now appears in lower case so update pytest
accordingly.

Signed-off-by: Simon Glass <sjg@chromium.org>

test/py/tests/test_spl.py

@@ -36,7 +36,7 @@ def test_spl(u_boot_console, ut_spl_subtest):
         cons = u_boot_console
         cons.restart_uboot_with_flags(['-u', '-k', ut_spl_subtest.split()[1]])
         output = cons.get_spawn_output().replace('\r', '')
-        assert 'Failures: 0' in output
+        assert 'failures: 0' in output
     finally:
         # Restart afterward in case a non-SPL test is run next. This should not
         # happen since SPL tests are run in their own invocation of test.py, but