logging: make sure to not change errno

Our log functions save errno and restore it. Restoring should be
at the very end of the __print_on_level() function, but
commit 6ae4a973 ("rpc: Report back first error message on failure")
messed with it.

Move errno restore at the end of the function.

travis-ci: success for Assorted nitpicks
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/log.c

@@ -227,10 +227,11 @@ static void __print_on_level(unsigned int loglevel, const char *format, va_list
 			break;
 		off += ret;
 	}
-	errno =  __errno;
 
 	if (loglevel == LOG_ERROR)
 		log_note_err(buffer + buf_off);
+
+	errno =  __errno;
 }
 
 void print_on_level(unsigned int loglevel, const char *format, ...)