avoid_unnecessary_return_variable

An avoid_unnecessary_return_variable rule which forbids returning an immutable variable if it can be rewritten in return statement itself.

See more here: https://github.com/solid-software/solid_lints/issues/92

Example

BAD:

void x() {
  final y = 1;

  return y;
}

GOOD:

void x() {
  return 1;
}