typo fixes: occuring -> occurring

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/include/asm-arm/thread_info.h b/include/asm-arm/thread_info.h
index c46b5c8..8a7554f 100644
--- a/include/asm-arm/thread_info.h
+++ b/include/asm-arm/thread_info.h
@@ -116,7 +116,7 @@
 
 /*
  * We use bit 30 of the preempt_count to indicate that kernel
- * preemption is occuring.  See include/asm-arm/hardirq.h.
+ * preemption is occurring.  See include/asm-arm/hardirq.h.
  */
 #define PREEMPT_ACTIVE	0x40000000