largefile: rearrange conditionnal in `synclfdirstate`

We can liquidate the special case early, so do we.

Differential Revision: https://phab.mercurial-scm.org/D11141

hgext/largefiles/lfutil.py

@@ -550,11 +550,11 b' def getstandinsstate(repo):'
 
 def synclfdirstate(repo, lfdirstate, lfile, normallookup):
     lfstandin = standin(lfile)
-    if lfstandin in repo.dirstate:
+    if lfstandin not in repo.dirstate:
+        lfdirstate.drop(lfile)
+    else:
         stat = repo.dirstate._map[lfstandin]
         state, mtime = stat.state, stat.mtime
-    else:
-        state, mtime = b'?', -1
     if state == b'n':
         if normallookup or mtime < 0 or not repo.wvfs.exists(lfile):
             # state 'n' doesn't ensure 'clean' in this case
@@ -567,8 +567,6 b' def synclfdirstate(repo, lfdirstate, lfi'
         lfdirstate.remove(lfile)
     elif state == b'a':
         lfdirstate.add(lfile)
-    elif state == b'?':
-        lfdirstate.drop(lfile)
 
 
 def markcommitted(orig, ctx, node):