ktest.pl: Give back console on Ctrt^C on monitor

When monitoring the console output, the stdout is being redirected to do
so. If Ctrl^C is hit during this mode, the stdout is not back to the
console, the user does not see anything they type (no echo).

Add "end_monitor" to the SIGINT interrupt handler to give back the console
on Ctrl^C.

Cc: [e-mail]
Fixes: 9f2cdcbbb90e7 ("ktest: Give console process a dedicated tty")
Signed-off-by: Steven Rostedt <[e-mail]>

tools/testing/ktest/ktest.pl

···
 }
 
 sub cancel_test {
+    if ($monitor_cnt) {
+	end_monitor;
+    }
     if ($email_when_canceled) {
 	my $name = get_test_name;
 	send_email("KTEST: Your [$name] test was cancelled",