infiniband: drop unknown function from core_priv.h

Delete ibnl_chk_listeners() and its kernel-doc comments from the
core_priv.h header file.  There is no such function.

Fixes: 233c1955835b ("RDMA/netlink: Reduce exposure of RDMA netlink functions")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/core_priv.h

@@ -191,13 +191,6 @@ void ib_sa_cleanup(void);
 int rdma_nl_init(void);
 void rdma_nl_exit(void);
 
-/**
- * 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.
- */
-int ibnl_chk_listeners(unsigned int group);
-
 int ib_nl_handle_resolve_resp(struct sk_buff *skb,
 			      struct nlmsghdr *nlh,
 			      struct netlink_ext_ack *extack);