Diagnotic improvement to soft dependency structure management.

The soft updates diagnotic code keeps a list for each type of soft
update dependency. When a new block is allocated for a file it is
initially tracked by a "newblk" dependency. The "newblk" dependency
eventually becomes either an "allocdirect" dependency or an "indiralloc"
dependency. The diagnotic code failed to move the "newblk" from the list
of "newblk"s to its new type list.

No functional change intended.

Reviewed by: Chuck Silvers (as part of a larger change)
Tested by: Peter Holm (as part of a larger change)
Sponsored by: Netflix