ktest.pl: Have ktest.pl pass -r to config-bisect.pl to reset bisect

If config-bisect.pl sees that a config_bisect has already been started, it
will ask on the command line if it should bisect or not. This will mess up
running config_bisect from ktest.pl.

Have ktest.pl pass in '-r' to config-bisect.pl and have config-bisect.pl
recognize that to reset without asking.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tools/testing/ktest/config-bisect.pl

@@ -52,11 +52,11 @@
 
 # If "good" or "bad" is not stated at the end, it will copy the good and
 # bad configs to the .tmp versions. If a .tmp version already exists, it will
-# warn before writing over them. If the last config is labeled "good", then
-# it will copy it to the good .tmp version. If the last config is labeled
-# "bad", it will copy it to the bad .tmp version. It will continue this until
-# it can not merge the two any more without the result being equal to either
-# the good or bad .tmp configs.
+# warn before writing over them (-r will not warn, and just write over them).
+# If the last config is labeled "good", then it will copy it to the good .tmp
+# version. If the last config is labeled "bad", it will copy it to the bad
+# .tmp version. It will continue this until it can not merge the two any more
+# without the result being equal to either the good or bad .tmp configs.
 
 my $start = 0;
 my $val = "";
@@ -67,6 +67,7 @@ my $tree = $pwd;
 my $build;
 
 my $output_config;
+my $reset_bisect;
 
 sub usage {
     print << "EOF"
@@ -654,6 +655,10 @@ while ($#ARGV >= 0) {
 	$tree = $val;
     }
 
+    elsif ($opt eq "-r") {
+	$reset_bisect = 1;
+    }
+
     elsif ($opt eq "-h") {
 	usage;
     }
@@ -721,10 +726,12 @@ if ($start) {
 	    $p = "$p$bad exists\n";
 	}
 
+	if (!defined($reset_bisect)) {
 	    if (!read_yn "${p}Overwrite and start new bisect anyway?") {
 		exit (-1);
 	    }
 	}
+    }
     run_command "cp $good_start $good" or die "failed to copy to $good\n";
     run_command "cp $bad_start $bad" or die "faield to copy to $bad\n";
 } else {

tools/testing/ktest/ktest.pl

@@ -3127,10 +3127,14 @@ sub config_bisect_end {
 
 sub run_config_bisect {
     my ($good, $bad, $last_result) = @_;
+    my $reset = "";
     my $cmd;
     my $ret;
 
-    run_command "$builddir/tools/testing/ktest/config-bisect.pl -b $outputdir $good $bad $last_result", 1;
+    if (!length($last_result)) {
+	$reset = "-r";
+    }
+    run_command "$builddir/tools/testing/ktest/config-bisect.pl $reset -b $outputdir $good $bad $last_result", 1;
 
     # config-bisect returns:
     #   0 if there is more to bisect