staging: sm750fb: compress return logic

Using Coccinelle script, compress return logic to return a value
directly rather than doing an assignment and returning the variable.
Remove unnecessary variable declaration by hand.

Coccinelle script:

@@
local idexpression ret;
expression e;
@@

-ret =
+return
     e;
-return ret;

Signed-off-by: Elizabeth Ferdman <gnudevliz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>