staging: wilc1000: fix error handling in wilc_debugfs_init()

We can just ignore the return value from debugfs_create_dir() and
debugfs_create_file(). The second one already interanlly checks the dentry
created by the first before creating the file.

debugfs was written so it would be easy to use, no need for error checking.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>