commit header lines...

Some of you may have noticed, but I have been editing commit
header lines to be more in tune with what people use in the
rest of the kernel and what is facilitated best by the tools.

This basically means:

subsystem: Commit description

Where "subsystem" is in lower case and not surrounded by
"[" and "]" as we previously did in the past.

Please try to adhere to this in your patch submissions as
it saves work for me.

Thanks.