x86, asmlinkage: Make dump_stack visible

dump_stack is used from assembler code, so make it visible.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1375740170-7446-15-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 22c7052..e6131a78 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -200,7 +200,7 @@
 }
 #endif
 
-extern void dump_stack(void) __cold;
+extern asmlinkage void dump_stack(void) __cold;
 
 #ifndef pr_fmt
 #define pr_fmt(fmt) fmt