drive_encryption: Fix ata passthrough12 verify

drive_encryption: Fix ata passthrough12 verify

Based on documentation SCSI Primary Commands - 4 (SPC-4) only first 7 bits
of first byte in sense data are used to store response code. The current
verification uses all 8 bits for comparison of response code.

Incorrect verification may make impossible to use SATA disks with IMSM,
because IMSM requires verification of the encryption state before use.

There was issue in kernel libata [1]. This issue hides bug in mdadm because
last bit was not set.

Example output with affected mdadm:

          Port3 : /dev/sde (BTPR212503EK120LGN)
mdadm: Failed ata passthrough12 ioctl. Device: /dev/sde.
mdadm: Failed to get drive encryption information

The fix is use the first 7 bits of Byte 0, to compare with the expected
values.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/libata/linux.git/commit/?id=38dab832c3f4

Fixes: df38df3052c3 ("Add reading SATA encryption information")
Signed-off-by: Blazej Kucman <blazej.kucman@intel.com>