[PATCH] hpet: remove superfluous indirections

In the hpet_ioctl_common() function, devp->hd_hpets is already cached in the
hpetp variable, so we can use just that.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>