restorer: Report child's death reason correctly

E.g, if child was killed by SIGSEGV, this message
previously was "exited, status=11", as si_code == CLD_DUMPED == 3
in this case will result in (si_code & CLD_KILLED) == (si_code & 1).
Which is misleading as you may try to look for exit() calls
with 11 arg.
Correct if to compare si_code with CLD_*.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/pie/restorer.c

@@ -102,12 +102,18 @@ static void sigchld_handler(int signal, siginfo_t *siginfo, void *data)
 		if (siginfo->si_pid == zombies[i])
 			return;
 
-	if (siginfo->si_code & CLD_EXITED)
-		r = " exited, status=";
-	else if (siginfo->si_code & CLD_KILLED)
-		r = " killed by signal ";
+	if (siginfo->si_code == CLD_EXITED)
+		r = "exited, status=";
+	else if (siginfo->si_code == CLD_KILLED)
+		r = "killed by signal";
+	else if (siginfo->si_code == CLD_DUMPED)
+		r = "terminated abnormally with";
+	else if (siginfo->si_code == CLD_TRAPPED)
+		r = "trapped with";
+	else if (siginfo->si_code == CLD_STOPPED)
+		r = "stopped with";
 	else
-		r = "disappeared with ";
+		r = "disappeared with";
 
 	pr_info("Task %d %s %d\n", siginfo->si_pid, r, siginfo->si_status);