block: Clarify error messages pertaining to 'node-name'

block: Clarify error messages pertaining to 'node-name'

Some error messages contain ambiguous representations of the 'node-name'
parameter. This can be particularly confusing when exchanging QMP
messages (C = client, S = server):

C: {"execute": "block_resize", "arguments": { "device": "my_file", "size": 26843545600 }}
S: {"error": {"class": "GenericError", "desc": "Cannot find device=my_file nor node_name="}}
                                                                               ^^^^^^^^^

This error message suggests one could send a message with a key called
'node_name':

C: {"execute": "block_resize", "arguments": { "node_name": "my_file", "size": 26843545600 }}
                                               ^^^^^^^^^

but using the underscore is actually incorrect, the parameter should be
'node-name':

S: {"error": {"class": "GenericError", "desc": "Parameter 'node_name' is unexpected"}}

This behavior was uncovered in bz1651437, but I ended up going down a
rabbit hole looking for other areas where this miscommunication might
occur and changing those accordingly as well.

Fixes: https://bugzilla.redhat.com/1651437
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <20210305151929.1947331-2-ckuehl@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>