[PATCH] IB/ipath: allow diags on any unit

There is no longer a /dev/ipath_diag file; instead, there's
/dev/ipath_diag0, 1, etc.

It's still not possible to have diags run on more than one unit at a time,
but that's easy to fix at some point.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Cc: "Michael S. Tsirkin" <mst@mellanox.co.il>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>