net/embms-kernel : Fix for embms-kernel compilation issues

Resolved warning treated as errors. Removed unused variables
and corrected return type of ioctl function

Change-Id: I6d1e4ed0f7ac8a3459aeabd2e17eef6a2d049bad
Acked-by: Anvitha Nandigam <anandiga@qti.qualcomm.com>
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>