staging: wilc1000: Process WARN, INFO options of debug levels from user

This patch enables setting the module's debug options WARN and INFO in the
debugfs file 'wilc_debug_level'.  This functionality allows the user to
enable logging of warnings and other information.  Before this change,
writes to this debugfs file set only one option - DEBUG.  Another option
that is enabled by default is ERR.

As a side effect, this patch removes the 'sparse' warning -
'warning: incorrect type in argument 2 (different address spaces)'.

Signed-off-by: Chandra S Gorentla <csgorentla@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>