verify: reference the correct linkrev when a filelog is missing
when a filelog is missing, the first bad revision is the first revision
where the filelog is referenced, not 0.
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
created new head
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
adding b
created new head
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
adding b
created new head