checkpatch: remove email address comment from email address comparisons

About 2% of the last 100K commits have email addresses that include an
RFC2822 compliant comment like:

	Peter Zijlstra (Intel) <peterz@infradead.org>

checkpatch currently does a comparison of the complete name and address to
the submitted author to determine if the author has signed-off and emits a
warning if the exact email names and addresses do not match.

Unfortunately, the author email address can be written without the comment
like:

	Peter Zijlstra <peterz@infradead.org>

Add logic to compare the comment stripped email addresses to avoid this
warning.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ebaa2f7c8f94e25520981945cddcc1982e70e072.camel@perches.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>