loginuid: save value of loginuid from a target userns

It is restored from the userns.

21:22:31.443:     4: FAIL: loginuid.c:93: loginuid value 3 is different after restore: 100003

Cc: Dmitry Safonov <dsafonov@odin.com>
Signed-off-by: Andrew Vagin <avagin@virtuozzo.com>
Reviewed-by: Dmitry Safonov <dsafonov@odin.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-dump.c

@@ -331,6 +331,7 @@ static int dump_pid_misc(pid_t pid, TaskCoreEntry *tc)
 
 	tc->has_loginuid = true;
 	tc->loginuid = parse_pid_loginuid(pid, &ret);
+	tc->loginuid = userns_uid(tc->loginuid);
 	/*
 	 * loginuid dumping is critical, as if not correctly
 	 * restored, you may loss ability to login via SSH to CT