intel-hid: allocate correct amount of memory for private struct

intel-hid: allocate correct amount of memory for private struct

BugLink: http://bugs.launchpad.net/bugs/1589886
We want the size of the struct, not of a pointer to it. To be future
proof, just dereference the pointer to get the desired type.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
(cherry picked from commit e8b69a51b4e72a168e8b3bc5fcac39a7de339864)
Signed-off-by: Alex Hung <alex.hung@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>