staging: greybus: arche-platform: compress return logic into one line

Modify return statement to use the value being returned directly instead of
assigning it first to 'ret' and returning this variable. Coccinelle semantic
patch used:

@@
expression e;
local idexpression ret;
@@

-ret =
+return
	e;
-return ret;

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>