powerpc/pseries: Simplify vpa deregistration functions

The VPA, SLB shadow and DTL degistration functions do not need an
address, so simplify things and remove it.

Also cleanup pseries_kexec_cpu_down a bit by storing the cpu IDs
in local variables.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/pseries/plpar_wrappers.h b/arch/powerpc/platforms/pseries/plpar_wrappers.h
index a6921ae..41c24c1 100644
--- a/arch/powerpc/platforms/pseries/plpar_wrappers.h
+++ b/arch/powerpc/platforms/pseries/plpar_wrappers.h
@@ -53,9 +53,9 @@
 	return plpar_hcall_norets(H_REGISTER_VPA, flags, cpu, vpa);
 }
 
-static inline long unregister_vpa(unsigned long cpu, unsigned long vpa)
+static inline long unregister_vpa(unsigned long cpu)
 {
-	return vpa_call(0x5, cpu, vpa);
+	return vpa_call(0x5, cpu, 0);
 }
 
 static inline long register_vpa(unsigned long cpu, unsigned long vpa)
@@ -63,9 +63,9 @@
 	return vpa_call(0x1, cpu, vpa);
 }
 
-static inline long unregister_slb_shadow(unsigned long cpu, unsigned long vpa)
+static inline long unregister_slb_shadow(unsigned long cpu)
 {
-	return vpa_call(0x7, cpu, vpa);
+	return vpa_call(0x7, cpu, 0);
 }
 
 static inline long register_slb_shadow(unsigned long cpu, unsigned long vpa)