Fix NSEDoc error messages, except for some "documenting undefined parameter"

that happen when one function is defined to be another by assignment.

nselib/ssh2.lua

@@ -40,7 +40,7 @@ transport.build = function( payload )
 end
 
 --- Extract the payload from a received SSH-2 packet.
---@param received SSH2 packet.
+--@param packet received SSH2 packet.
 --@return payload of the SSH2 packet.
 transport.payload = function( packet )
   local packet_length, padding_length, payload_length, payload, offset