net: ipa: don't proceed to out-of-bound write

GCC 12 seems upset that we check ipa_irq against array bound
but then proceed, anyway:

drivers/net/ipa/ipa_interrupt.c: In function ‘ipa_interrupt_add’:
drivers/net/ipa/ipa_interrupt.c:196:27: warning: array subscript 30 is above array bounds of ‘void (*[30])(struct ipa *, enum ipa_irq_id)’ [-Warray-bounds]
  196 |         interrupt->handler[ipa_irq] = handler;
      |         ~~~~~~~~~~~~~~~~~~^~~~~~~~~
drivers/net/ipa/ipa_interrupt.c:42:27: note: while referencing ‘handler’
   42 |         ipa_irq_handler_t handler[IPA_IRQ_COUNT];
      |                           ^~~~~~~

Reviewed-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220519004417.2109886-1-kuba@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>