target-arm: Fix unreachable code in gicv3_class_name()

Coverity complains that the exit() in gicv3_class_name()
can be unreachable, because if TARGET_AARCH64 is defined
then all code paths return before reaching it. Move the
exit() up to the error_report() that it belongs with.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Shannon Zhao <shannon.zhao@linaro.org>
Message-id: 1468260552-8400-1-git-send-email-peter.maydell@linaro.org

target-arm/machine.c

@@ -340,10 +340,9 @@ const char *gicv3_class_name(void)
 #else
         error_report("KVM GICv3 acceleration is not supported on this "
                      "platform");
+        exit(1);
 #endif
     } else {
         return "arm-gicv3";
     }
-
-    exit(1);
 }