[PATCH] x86_64: fix early oops printing

Fix early oopses

Without this very early oopses crash recursively while trying
to figure out the current CPU number.

Based on a patch by James Cleverdon.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-x86_64/smp.h

@@ -109,6 +109,11 @@ static inline int x86_apicid_to_cpu(u8 apicid)
       	if (x86_cpu_to_apicid[0] == BAD_APICID)
 		return 0;
 
+		  /* No entries in x86_cpu_to_apicid?  Either no MPS|ACPI,
+          * or called too early.  Either way, we must be CPU 0. */
+      	if (x86_cpu_to_apicid[0] == BAD_APICID)
+			return 0;
+
 	return -1;
 }