nvme/rdma: print getaddrinfo() error if it fails

gai_strerror() is documented as thread-safe, so this should be safe to
use from a library.

Change-Id: Ia0ec0b5c387db8993dd1ba3a3029562f25cc210d
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/369642
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

lib/nvme/nvme_rdma.c

@@ -542,7 +542,7 @@ nvme_rdma_parse_addr(struct sockaddr_storage *sa, int family, const char *addr,
 
 	ret = getaddrinfo(addr, service, &hints, &res);
 	if (ret) {
-		SPDK_ERRLOG("getaddrinfo failed - invalid hostname or IP address\n");
+		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(ret), ret);
 		return ret;
 	}