libblkid: fix regression in setting BLOCK_SIZE value

libblkid: fix regression in setting BLOCK_SIZE value

In the stable version, the BLOCK_SIZE attribute is
unconditionally set when probing the device.

Commit c9b2297eb1f357d9bc9989aacc874f218081fcb8 added
a new FSINFO flag and conditionally set the BLOCK_SIZE
attribute only when it is used.

This breaks the ABI interface. Cryptsetup reencrypt code
depends on checking the minimal accessible FS block
to prevent the destruction of the filesystem if a user
requests reencryption to a larger sector than
the filesystem can handle.

This patch removes the condition to make ABI compatible
again (as we cannot add FSINFO bit retrospectively).

Signed-off-by: Milan Broz <gmazyland@gmail.com>