Updated ui tests.

Author: Alexander Regueiro

src/test/ui/keyword/keyword-self-as-identifier.stderr

@@ -4,7 +4,6 @@ error[E0531]: cannot find unit struct/variant or constant `Self` in this scope
 LL |     let Self = 22; //~ ERROR cannot find unit struct/variant or constant `Self` in this scope
    |         ^^^^ not found in this scope
 
-error: aborting due to 1 previous error
+error: aborting due to previous error
 
-Some errors occurred: E0531, E0658.
-For more information about an error, try `rustc --explain E0531`.
+For more information about this error, try `rustc --explain E0531`.

src/test/ui/self/self_type_keyword-2.stderr

@@ -24,5 +24,5 @@ LL |         Foo { x: Self } => (),
 
 error: aborting due to 4 previous errors
 
-Some errors occurred: E0432, E0531, E0658.
+Some errors occurred: E0432, E0531.
 For more information about an error, try `rustc --explain E0432`.