Corrections to the while-let example per review.

Author: androm3da

src/doc/book/if-let.md

@@ -58,8 +58,7 @@ if let Some(x) = option {
 ## `while let`
 
 In a similar fashion, `while let` can be used when you want to conditionally
-loop over an iterator as long as a value matches a certain pattern. It turns 
-code like this:
+loop  as long as a value matches a certain pattern. It turns code like this:
 
 ```rust
 # let option: Option<i32> = None;
@@ -74,9 +73,9 @@ loop {
 Into code like this:
 
 ```rust
-# let v: vec![1, 3, 5, 7, 9, ];
-# let mut it: v.iter();
-while let Some(x) = it.next() {
+let v: vec![1, 3, 5, 7, 11, ];
+let mut iter: v.iter();
+while let Some(x) = iter.next() {
     println!("{}", x);
 }
 ```