[SCSI] ipr: Fix adapter microcode update DMA mapping leak

If the write buffer command that is issued to the ipr adapter
to update its microcode fails for some reason, the DMA buffer
will never get unmapped. Move the pci_map/unmap out of the
IOA reset job so that the buffer is always clearly mapped
and unmapped.

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