RDMA/netlink: Simplify netlink listener existence check

All users of rdma_nl_chk_listeners() are interested to get boolean answer
if netlink socket has listeners, so update all places to boolean function.

Signed-off-by: Leon Romanovsky <[e-mail]>
Reviewed-by: Dennis Dalessandro <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

drivers/infiniband/core/addr.c

···
 static int ib_nl_fetch_ha(struct rdma_dev_addr *dev_addr,
 			  const void *daddr, u32 seq, u16 family)
 {
-	if (rdma_nl_chk_listeners(RDMA_NL_GROUP_LS))
+	if (!rdma_nl_chk_listeners(RDMA_NL_GROUP_LS))
 		return -EADDRNOTAVAIL;
 
 	return ib_nl_ip_send_msg(dev_addr, daddr, seq, family);

drivers/infiniband/core/netlink.c

···
 	const struct rdma_nl_cbs   *cb_table;
 } rdma_nl_types[RDMA_NL_NUM_CLIENTS];
 
-int rdma_nl_chk_listeners(unsigned int group)
+bool rdma_nl_chk_listeners(unsigned int group)
 {
-	return (netlink_has_listeners(nls, group)) ? 0 : -1;
+	return netlink_has_listeners(nls, group);
 }
 EXPORT_SYMBOL(rdma_nl_chk_listeners);
 

drivers/infiniband/core/sa_query.c

···
 
 	if ((query->flags & IB_SA_ENABLE_LOCAL_SERVICE) &&
 	    (!(query->flags & IB_SA_QUERY_OPA))) {
-		if (!rdma_nl_chk_listeners(RDMA_NL_GROUP_LS)) {
+		if (rdma_nl_chk_listeners(RDMA_NL_GROUP_LS)) {
 			if (!ib_nl_make_request(query, gfp_mask))
 				return id;
 		}

include/rdma/rdma_netlink.h

···
 /**
  * Check if there are any listeners to the netlink group
  * @group: the netlink group ID
- * Returns 0 on success or a negative for no listeners.
+ * Returns true on success or false if no listeners.
  */
-int rdma_nl_chk_listeners(unsigned int group);
+bool rdma_nl_chk_listeners(unsigned int group);
 #endif /* _RDMA_NETLINK_H */