Fixed create_vmknic hosts arg and passed args to method

Attached change is to fix:

> vds.create_vmknic /vcs01.local/dc/networks/vds01/portgroups/vmk1 /vcs01.local/dc/networks/vds01/hosts/esx01.local
ArgumentError: wrong number of arguments (2 for 3)
/Users/flands/.rvm/gems/ruby-1.9.3-p362/gems/rvc-1.7.0/lib/rvc/modules/vds.rb:642:in `create_vmknic'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/gems/rvc-1.7.0/lib/rvc/command.rb:42:in `invoke'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/gems/rvc-1.7.0/lib/rvc/shell.rb:126:in `eval_command'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/gems/rvc-1.7.0/lib/rvc/shell.rb:73:in `eval_input'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/gems/rvc-1.7.0/bin/rvc:160:in `<top (required)>'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/bin/rvc:19:in `load'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/bin/rvc:19:in `<main>'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/bin/ruby_noexec_wrapper:14:in `eval'
/Users/flands/.rvm/gems/ruby-1.9.3-p362/bin/ruby_noexec_wrapper:14:in `<main>'