CVE-2025-38530: Out-of-bounds Read

In the Linux kernel, the following vulnerability has been resolved:

comedi: pcl812: Fix bit shift out of bounds

When checking for a supported IRQ number, the following test is used:

if ((1 << it->options[1]) & board->irq_bits) {

However, `it->options[i]` is an unchecked `int` value from userspace, so the shift amount could be negative or out of bounds. Fix the test by requiring `it->options[1]` to be within bounds before proceeding with the original test. Valid `it->options[1]` values that select the IRQ will be in the range [1,15]. The value 0 explicitly disables the use of interrupts.