irqchip/gic-v5: Check get_logical_index() return value in MADT IAFFID parsing

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v5: Check get_logical_index() return value in MADT IAFFID parsing In gic_acpi_parse_iaffid() a given MADT GICC entry might not correspond to a logical cpu recognized by the kernel, resulting in the cpu variable initialization to an error value. Currently, the get_logical_index() return value is not checked for failure, which might result in out-of-bounds memory corruption while trying to index a per_cpu variable array. Add a check to evaluate get_logical_index() return value.