[SCSI] isci: Fix a infinite loop.

It seems the "phy_index++;" have been placed in wrong place, without it
the while circle up will do a infinite loop.

Signed-off-by: Xinghai Yu <yuxinghai@cn.fujitsu.com>
Acked-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>