Updated scsi path<->hctl utils for PSCSI TYPE_DISK/TYPE_ROM on modern kernels
Updated scsi path<->hctl utils for PSCSI TYPE_DISK/TYPE_ROM on modern kernels

* Functions rtslib.utils.convert_scsi_path_to_hctl() and
  rtslib.utils.convert_scsi_hctl_to_path() were using
     '/sys/class/scsi_device/$SCSI_HCTL/device/block/$SCSI_DEVICE/'
  which is now absent from modern kernels. Now using
     '/sys/block/$SCSI_DEVICE/device/scsi_device/$SCSI_HCTL'
  which is present in both 2.6x and all 3.x kernels.

mikenawrocki/rtslib-fb,mikenawrocki/rtslib-fb,agrover/rtslib-fb,cvubrugier/rtslib-fb