drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer

Fix bogus NULL checks on the return value of acpi_cpu_get_madt_gicc()
by checking for a 0 'gicc->performance_interrupt' value instead.

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>