ktest: add ability to skip during BISECT_MANUAL

When doing a manual bisect, a build can fail or a test can be inconclusive.
In these cases it would be helpful to be able to skip the test entirely.

Link: http://lkml.kernel.org/r/1409164021-2136-1-git-send-email-chris.j.arges@canonical.com

Reviewed-by: Satoru Takeuchi <satoru.takeuchi@gmail.com>
Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

tools/testing/ktest/ktest.pl

@@ -2338,15 +2338,17 @@ sub success {
 
 sub answer_bisect {
     for (;;) {
-	doprint "Pass or fail? [p/f]";
+	doprint "Pass, fail, or skip? [p/f/s]";
 	my $ans = <STDIN>;
 	chomp $ans;
 	if ($ans eq "p" || $ans eq "P") {
 	    return 1;
 	} elsif ($ans eq "f" || $ans eq "F") {
 	    return 0;
+	} elsif ($ans eq "s" || $ans eq "S") {
+	    return -1;
 	} else {
-	    print "Please answer 'P' or 'F'\n";
+	    print "Please answer 'p', 'f', or 's'\n";
 	}
     }
 }