align nfsdumpstate column output

There are scenarios where an NFS client will mount an NFSv4 export
without specifying a callback address.

When running nfsdumpstate under this circumstance, the column output is
shifted incorrectly which places the "ClientID" value underneath the
"Clientaddr" column.

This diff is a small cosmetic change that prints a blank in the
"Clientaddr" column and ensures the data for the columns are aligned
appropriately.

Submitted by:	Caleb St. John
Reviewed by:	sef (previous version)
MFC after:	3 days
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D18958

usr.sbin/nfsdumpstate/nfsdumpstate.c

@@ -162,6 +162,9 @@ dump_openstate(void)
 				printf("%-45s ", " ");
 			break;
 #endif
+		default:
+			printf("%-45s ", " ");
+			break;
 		}
 		for (i = 0; i < dp[cnt].ndcl_clid.nclid_idlen; i++)
 			printf("%02x", dp[cnt].ndcl_clid.nclid_id[i]);