[IB] mthca: fix off by one in clr_int calculation

We should use the first word of the clear interrupt register if
the bit we're after is < 32, not < 31.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
1 file changed