i2o: fix notifiers when max_drivers is configured

Maximum number of I2O drivers which could be registered is configurable by
max_drivers module parameter.

But the module parameter is ignored and default value (I2O_MAX_DRIVERS = 8)
is used in the loops to notify all registered drivers.

Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>