staging: wilc1000: Return correct error codes

staging: wilc1000: Return correct error codes

This change has been made with the goal that kernel functions should
return something more descriptive than -1 on failure.

The return value on an alloc_etherdev failure should be -ENOMEM,
and not -1.

This was found using Coccinelle. A simplified version of the semantic
patch used is:

//<smpl>
@@
expression *e;
identifier l1;
@@

e = alloc_etherdev(...);
if (e == NULL) {
...
return
- -1
+ -ENOMEM
;
}
//</smpl

Furthermore, introduced `ret` variable to store and return the
corresponding error code returned by register_netdev on failure.

The two call sites store the return value in a variable which only
checks that the value is non-zero, hence no change is required at
the call sites.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>