[SCSI] advansys: Update resource management

Make sure the resources are reserved and released by all the callers of
advansys_board_found().  This eliminates the check_region-style race.
It also allows us to use the pci_request_regions() API.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>