Add the current command to the command information

Add the current command to the command information

I wanted to make it so I can be ignorant of a commands invocation string, so
I tried to use CMD_CURRENT (aka cmd->current) which is supposed to house a
pointer to the current command.  It turns out that this wasn't being set.

This patch adds the current command structure to the command invocation
structure before sending it along to the command handler.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>