microblaze: intc: Refactor DT sanity check

Avoid funky casts and arithmetic.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/kernel/intc.c

@@ -157,7 +157,7 @@ static int __init xilinx_intc_of_init(struct device_node *intc,
 		return ret;
 	}
 
-	if (intr_mask > (u32)((1ULL << nr_irq) - 1))
+	if (intr_mask >> nr_irq)
 		pr_info(" ERROR: Mismatch in kind-of-intr param\n");
 
 	pr_info("%s: num_irq=%d, edge=0x%x\n",