Removed trailing white spaces

Author: jwhite927

src/librustc_error_codes/error_codes/E0637.md

@@ -24,7 +24,7 @@ struct A<const N: &u8>;
 //~^ ERROR `&` without an explicit lifetime name cannot be used here
 trait B {}
 
-impl<const N: &u8> A<N> { 
+impl<const N: &u8> A<N> {
 //~^ ERROR `&` without an explicit lifetime name cannot be used here
     fn foo<const M: &u8>(&self) {}
     //~^ ERROR `&` without an explicit lifetime name cannot be used here
@@ -38,7 +38,7 @@ fn bar<const N: &u8>() {}
 }
 ```
 
-Const generics cannot be borrowed without specifying a lifetime.The 
+Const generics cannot be borrowed without specifying a lifetime.The
 compiler handles memory allocation of constants differently than that of
 variables and it cannot infer the lifetime of the borrowed constant.
 To fix this, explicitly specify a lifetime for the const generic.