coccinelle: irqf_oneshot.cocci: Improve the generated commit log

Improve the commit log of the generated patch by mentioning the commit
log that makes threaded IRQs without a primary handler to be requested
with the IRQF_ONESHOT flag.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked- by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>