largefile: directly use set_untracked() for removing files

This is new shiny API.

Differential Revision: https://phab.mercurial-scm.org/D11109

hgext/largefiles/overrides.py

@@ -227,9 +227,7 b' def removelargefiles(ui, repo, isaddremo'
         repo[None].forget(remove)
 
         for f in remove:
-            lfutil.synclfdirstate(
-                repo, lfdirstate, lfutil.splitstandin(f), False
-            )
+            lfdirstate.set_untracked(lfutil.splitstandin(f))
 
         lfdirstate.write()