filemerge: clean up some dead code

We now exit early if we do a premerge, so extra checks are no longer necessary.

mercurial/filemerge.py

@@ -522,12 +522,8 b' def _filemerge(premerge, repo, mynode, o'
             # complete if premerge successful (r is 0)
             return not r, r
 
-        if not r:  # premerge successfully merged the file
-            needcheck = False
-        else:
-            needcheck, r = func(repo, mynode, orig, fcd, fco, fca, toolconf,
-                                files, labels=labels)
-
+        needcheck, r = func(repo, mynode, orig, fcd, fco, fca, toolconf, files,
+                            labels=labels)
         if needcheck:
             r = _check(r, ui, tool, fcd, files)