dm: fix bio-based DM IO accounting for split bios
Bugzilla: https://bugzilla.redhat.com/2051798
Tested: Verified preoper IO accounting with split bios
Upstream Status: kernel/git/torvalds/linux.git
Pull in upstream code to clean up device-mappers IO accounting after bio splits.
Signed-off-by: Benjamin Marzinski bmarzins@redhat.com
Edited by Benjamin Marzinski