IB/ipath: Better comment for rmb() in ipath_intr()
IB/ipath: Better comment for rmb() in ipath_intr()

An internal code review found the comment here lacking -- update it with 
more specifics of how and why the rmb() is there.

Signed-off-by: Arthur Jones <1fdd90beab4a9c6c8f3744801c2f8c7877b007d1@qlogic.com>
Signed-off-by: Roland Dreier <91e9b5f7ca0bb6300133ed378670d64af90dde66@cisco.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas