[PATCH] Avoid writing the APIC ID register

A small birdie tells us that in the long run it may not be a good idea
to write the APIC ID register.  It might be read-only in some
hypothetical situation down the road.

arch/i386/kernel/apic.c

@@ -248,12 +248,6 @@ int __init verify_local_APIC(void)
 	 */
 	reg0 = apic_read(APIC_ID);
 	Dprintk("Getting ID: %x\n", reg0);
-	apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
-	reg1 = apic_read(APIC_ID);
-	Dprintk("Getting ID: %x\n", reg1);
-	apic_write(APIC_ID, reg0);
-	if (reg1 != (reg0 ^ APIC_ID_MASK))
-		return 0;
 
 	/*
 	 * The next two are just to see if we have sane values.