Remove duplicate semicolon in return statements

[adamreeve]

• I agree that my contribution may be licensed either under MIT or any version of LGPL license.

This is a minor tidy up to the generated code. Some of the expressions returned from ReturnTypeConverter implementations added a semicolon, but a semicolon is already added everywhere ReturnTypeToManagedExpression.Render is called.

This didn't cause any build failures but Rider would show red lines when viewing the generated code and complain about "unreachable code", referring to the empty statement before the second semicolon.

[badcel]

Thank you 👍