argo: lower level of noisy connection-refused log

Switch the log line to argo_dprintk() so it is enabled only in debug
environments, as it can spam the logs when a dom0 service using the Argo
hypercall tries to communicate with a domain that is still starting up.

Note that this also lowers the log level to debug when the argo_dprintk()
facility is enabled.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
Reviewed-by: Mykola Kvach <mykola_kvach@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>

xen/common/argo.c

@@ -2034,10 +2034,9 @@ sendv(struct domain *src_d, xen_argo_addr_t *src_addr,
                                         src_id.domain_id);
     if ( !ring_info )
     {
-        gprintk(XENLOG_ERR,
-                "argo: vm%u connection refused, src (vm%u:%x) dst (vm%u:%x)\n",
-                current->domain->domain_id, src_id.domain_id, src_id.aport,
-                dst_addr->domain_id, dst_addr->aport);
+        argo_dprintk("vm%u connection refused, src (vm%u:%x) dst (vm%u:%x)\n",
+                     current->domain->domain_id, src_id.domain_id, src_id.aport,
+                     dst_addr->domain_id, dst_addr->aport);
 
         ret = -ECONNREFUSED;
     }