parse-maintainers: Mark as executable

[ Upstream commit 611d61f9ac99dc9e1494473fb90117a960a89dfa ]

This makes the script more convenient to run.

Signed-off-by: Jonathan Neuschäfer <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

Author: neuschaefer