content: fix double-underscore typo in defer-panic-recover article

The typo produces an underscore “[…]order after_the surrounding[…]” at
http://blog.golang.org/defer-panic-and-recover

Change-Id: I0ab9be9cbef772c3ebff684e7de96fc4c2c802c6
Reviewed-on: https://go-review.googlesource.com/16477
Reviewed-by: Minux Ma <minux@golang.org>
diff --git a/content/defer-panic-and-recover.article b/content/defer-panic-and-recover.article
index 8e10c90..f43383a 100644
--- a/content/defer-panic-and-recover.article
+++ b/content/defer-panic-and-recover.article
@@ -67,7 +67,7 @@
 	    return
 	}
 
-2. _Deferred_function_calls_are_executed_in_Last_In_First_Out_order_after__the_surrounding_function_returns._
+2. _Deferred_function_calls_are_executed_in_Last_In_First_Out_order_after_the_surrounding_function_returns._
  
 This function prints "3210":