Remove variable assignment before return

Removes unnecessary local variable declaration or unnecessary variable
assignment before a return statement:
 - An explicit type is added for arrays.

Given:
int i = 0;
return i;

When:
Clean up the code enabling "Remove variable assignment before return"

Then:
return 0;

Also improve the wording for switch cleanup.

Change-Id: I26ddf89fa96458640e9e417a52e8f3177fe0d928
Signed-off-by: Fabrice Tiercelin <fabrice.tiercelin@yahoo.fr>