Merge the commandline options with the payload's datastore

Not sure why this wasn't happening before. Some output formats were
passing options to Msf::Simple::Payload#generate_simple, some weren't.
This probably fixes several latent bugs.

[FIXRM #7109]

msfpayload

@@ -117,6 +117,8 @@ rest.each do |x|
 	options[k] = v.to_s
 end
 
+payload.datastore.merge! options
+
 if (cmd =~ /^(p|y|r|d|c|j|x|b|v|w)/)
 	fmt = 'perl' if (cmd =~ /^p/)
 	fmt = 'ruby' if (cmd =~ /^y/)

msfvenom

@@ -300,6 +300,7 @@ if opts[:payload]
 				::Msf::Serializer::ReadableText.dump_options(payload,'    '))
 			exit
 		end
+		payload.datastore.merge! datastore
 	end
 end