When slub_debug is enabled kmalloc returns unaligned memory. XFS uses
this unaligned memory for its buffers (if an unaligned buffer crosses a
page, XFS frees it and allocates a full page instead - see the function
xfs_buf_allocate_memory).
dm-integrity checks if bv_offset is aligned on page size and this check
fail with slub_debug and XFS.
Fix this bug by removing the bv_offset check, leaving only the check for
bv_len.