dm integrity: fix deadlock with overlapping I/O

dm integrity: fix deadlock with overlapping I/O

dm-integrity will deadlock if overlapping I/O is issued to it, the bug
was introduced by commit f46fa52a89c5 ("dm integrity: implement fair
range locks").  Users rarely use overlapping I/O so this bug went
undetected until now.

Fix this bug by correcting, likely cut-n-paste, typos in
ranges_overlap() and also remove a flawed ranges_overlap() check in
remove_range_unlocked().  This condition could leave unprocessed bios
hanging on wait_list forever.

Cc: stable@vger.kernel.org # v4.19+
Fixes: f46fa52a89c5 ("dm integrity: implement fair range locks")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>