staging: media: davinci_vpfe: remove unnecessary ret variable

Simplified return of funcions by removing assignment of ret variable.

Coccinelle script used:

@@
local idexpression ret;
expression e;
@@

- ret = e;
- if(ret)
-       return ret;
+ if(e)
+       return e;

@@
local idexpression ret;
expression e;
@@

- ret = e;
- return ret;
+ return e;

@@
local idexpression ret;
expression e;
@@

- ret = e;
- if(ret){
+ if(e){
        ... when != ret
-       return ret;
+       return e;
}

@@
type T; identifier i;
@@
- T i;
... when != i

Signed-off-by: Thaissa Falbo <thaissa.falbo@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>