quick fix: fix build failure for release version

conflicting types for ‘vcpu_dumpreg’

Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>

hypervisor/arch/x86/guest/vcpu.c

@@ -611,7 +611,7 @@ void vcpu_dumpreg(void *data)
 	}
 }
 #else
-void vcpu_dumpreg(__unused struct vcpu *vcpu)
+void vcpu_dumpreg(__unused void *data)
 {
 	return;
 }