go_tutorial: change wording slightly and sync .txt and .html post-gofmt

Fixes #1211.

R=r, r2
CC=golang-dev
https://golang.org/cl/2635041

doc/go_tutorial.html

@@ -531,7 +531,7 @@ object.  We could write
     return n
 </pre>
 <p>
-but for simple structures like <code>File</code> it's easier to return the address of a nonce
+but for simple structures like <code>File</code> it's easier to return the address of a 
 composite literal, as is done here on line 21.
 <p>
 We can use the factory to construct some familiar, exported variables of type <code>*File</code>:

doc/go_tutorial.txt

@@ -420,7 +420,7 @@ object.  We could write
 	n.name = name
 	return n
 
-but for simple structures like "File" it's easier to return the address of a nonce
+but for simple structures like "File" it's easier to return the address of a 
 composite literal, as is done here on line 21.
 
 We can use the factory to construct some familiar, exported variables of type "*File":