test: check exit codes for criu criu lazy-pages

travis-ci: success for crtools: close a signal descriptor after passing a preparation stage (rev6)
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

test/zdtm.py

@@ -975,7 +975,7 @@ class criu:
 				ps_opts = ["--daemon", "--pidfile", "ps.pid",
 					   "--port", "12345", "--lazy-pages"]
 				self.__criu_act("page-server", opts = ps_opts)
-			self.__criu_act("lazy-pages", opts = lp_opts)
+			self.__lazy_pages_p = self.__criu_act("lazy-pages", opts = lp_opts, nowait = True)
 			r_opts += ["--lazy-pages"]
 
 		if self.__leave_stopped: