IB/ipath: Convert ipath_eep_sem semaphore to a mutex

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Acked-by: Michael Albaugh <Michael.Albaugh@qlogic.com>
Tested-by: Arthur Jones <arthur.jones@qlogic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>