staging: rts5208: Removed unnecessary return variable

This patch removes unnecessary return variables in switch statements.
This was done with Coccinelle:

@@ local idexpression ret; expression e1,e2; identifier label;
@@
switch ( ... ) {
case label : ...
- ret = e1;
- break;
+ return e1;
... default: ...
- ret = e2;
+ return e2;
... }
... when != ret
- return ret;
@@ type T; identifier x; @@
- T x;
... when != x

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>