scripts/get_maintainer.pl: fix possible infinite loop

scripts/get_maintainer.pl: fix possible infinite loop

commit 3c840c18bcd8efb37f1a565e83a9509e1ea5d105 upstream.

If MAINTAINERS section entries are misformatted, it was possible to have
an infinite loop.

Correct the defect by always moving the index to the end of section + 1

Also, exit check for exclude as soon as possible.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>