service: Change default socket path to /var/run/

This is where such stuff is typically placed.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/cr-service.h

@@ -3,7 +3,7 @@
 
 #include "protobuf/rpc.pb-c.h"
 
-#define CR_DEFAULT_SERVICE_ADDRESS "/tmp/criu_service.socket"
+#define CR_DEFAULT_SERVICE_ADDRESS "/var/run/criu_service.socket"
 #define MAX_MSG_SIZE 1024
 
 int cr_service(bool deamon_mode);