[SCSI] ipr: Prevent overlapped adapter resets

This patch fixes some scenarios where an ipr adapter
could get reset overlapped, which could cause very
long timeouts to occur, or PCI bus errors.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>