qlcnic: fix onchip memory access

Fix incorrect offset calculation and remove unnecessary remap
of the region in bar 0 to access onchip memory.

This was leading to read incorrect values by debug tools.

Signed-off-by: Dhananjay Phadke <dhananjay.phadke@qlogic.com>
Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>