spelling fixes: arch/x86_64/

Spelling fixes in arch/x86_64/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index b4a9b3d..b4c8873 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -201,7 +201,7 @@
 #define MSG(txt) ops->warning(data, txt)
 
 /*
- * x86-64 can have upto three kernel stacks: 
+ * x86-64 can have up to three kernel stacks: 
  * process stack
  * interrupt stack
  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack