Fixed errors during compilation of OpenWRT kernel modules

[robgar2001]

Hi Xianjun Jiao,

Compiling the driver for OpenWRT gave some errors. These are fixed in this commit and should not influence the default OpenWiFi behaviour.

The changes are mainly type casting and removing the static keyword from the module pointers. Some printf strings where wrongly formatted according to the compiler.

Kind regards,

Robbe Gaeremynck