arm: Remove hw_error() usages.

All of these hw_errors are fatal and indicate something wrong with
QEMU implementation.

Convert to g_assert_not_reached.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: 169194d09017e5725535d31a1507d454c0043706.1440842587.git.crosthwaite.peter@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 4ba5929..7da29f5 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -342,7 +342,7 @@
         }
         break;
     default:
-        hw_error("arm_cpu_set_irq: Bad interrupt line %d\n", irq);
+        g_assert_not_reached();
     }
 }
 
@@ -361,7 +361,7 @@
         kvm_irq |= KVM_ARM_IRQ_CPU_FIQ;
         break;
     default:
-        hw_error("arm_cpu_kvm_set_irq: Bad interrupt line %d\n", irq);
+        g_assert_not_reached();
     }
     kvm_irq |= cs->cpu_index << KVM_ARM_IRQ_VCPU_SHIFT;
     kvm_set_irq(kvm_state, kvm_irq, level ? 1 : 0);