dm bufio: delete outdated comment

This comment was true when dm-bufio was written but, since 4.3, bios can
now have arbitrary size and the driver splits them.

Signed-off-by: Mikulas Patocka <[e-mail]>
Signed-off-by: Mike Snitzer <[e-mail]>

drivers/md/dm-bufio.c

···
  *
  *	the memory must be direct-mapped, not vmalloced;
  *
- *	the I/O driver can reject requests spuriously if it thinks that
- *	the requests are too big for the device or if they cross a
- *	controller-defined memory boundary.
- *
  * If the buffer is small enough (up to DM_BUFIO_INLINE_VECS pages) and
  * it is not vmalloced, try using the bio interface.
  *