Staging: heci: fix some sparse warnings

This resolves a lot of the more obvious sparse warnings in the code.

There still are some major problems in the ioctl handlers dealing with
user and kernel pointers that this patch does not resolve, that needs to
be addressed still.

Also, the locking seems to be a bit strange in places, which sparse
points out, that too need to be resolved.

Cc: Anas Nashif <anas.nashif@intel.com>
Cc: Marcin Obara <marcin.obara@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>