genirq: Fix typo in struct comment

Remove redundant "e" in "assign(e)ments".

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240822123205.2186221-1-costa.shul@redhat.com