ktest: Copy the last good and bad configs in config_bisect

During the config_bisect, in case of failure, it is nice to have
the last good and bad .configs that were used. This would let
us restart the config_bisect from those configs.

Copy the last good config into the output dir as config_good,
and the last bad config as config_bad.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 08a875f..04a3227 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -1281,6 +1281,8 @@
 	    delete $config_list{$config};
 	}
     }
+    doprint "config copied to $outputdir/config_good\n";
+    run_command "cp -f $output_config $outputdir/config_good";
 }
 
 sub process_failed {
@@ -1358,6 +1360,8 @@
 
 	doprint "This config had a failure.\n";
 	doprint "Removing these configs that were not set in this config:\n";
+	doprint "config copied to $outputdir/config_bad\n";
+	run_command "cp -f $output_config $outputdir/config_bad";
 
 	# A config exists in this group that was bad.
 	foreach my $config (keys %config_list) {