nlm: Fix error messages for failed remote rpcbind contact

In case of a remote rpcbind connection timeout,
the NFS kernel lock manager emits an error message
along the lines of:

NLM: failed to contact remote rpcbind, stat = 5, port = 28416

In the Bugzilla PR, Garrett Wollman identified the following problems
with that error message:

• The error is in decimal, which can only be deciphered by reading the source code.
• The port number is byte-swapped.
• The error message does not identify the client the NLM is trying to communicate with.

Fix the shortcomings of the current error message by:

• Printing out the port number correctly.
• Mentioning the remote client.

The low-level decimal error remains an outstanding issue though.
It seems like the error strings describing the error codes live outside
of the kernel code currently.

PR: 244698
Reported by: wollman
Approved by: allanjude
Sponsored by: National Bureau of Economic Research
Sponsored by: Klara, Inc.
Co-authored-by: Mateusz Piotrowski <0mp@FreeBSD.org>