staging: ks7010: avoid CamelCase in fields of struct local_gain_t

Replace CamelCase fields of struct with underscores to comply
with the standard kernel coding style

Signed-off-by: Janusz Lisiecki <janusz.lisiecki@gmail.com>
Reviewed-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>