inifiband: Remove BKL from ipath_open()

cycle_kernel_lock() got pushed down to ipath_open(). I tried hard to
understand what it might protect, but finally gave up.

Roland noted that qlogic seems to have abandoned the ipath driver and
came to the following wise conclusion: "So I guess if the BKL stuff is
blocking you in any way, we can just drop it from ipath and leave it
as yet another race condition in a rotting old driver."

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <adad44tj090.fsf@cisco.com>
Cc: Roland Dreier <rdreier@cisco.com>