checkcopies: move 'movewithdir' initialisation right before its usage

checkcopies: move 'movewithdir' initialisation right before its usage

The 'movewithdir' had a lot of related logic all around the 'mergecopies'.
However it is actually never containing anything until the very last loop in
that function. We move the (simplified) variable definition there for clarity

--- a/mercurial/copies.py	Fri Oct 14 01:53:15 2016 +0200
+++ b/mercurial/copies.py	Tue Oct 11 02:15:23 2016 +0200
@@ -333,7 +333,6 @@
 
     # see _checkcopies documentation below for these dicts
     copy1, copy2 = {}, {}
-    movewithdir1, movewithdir2 = {}, {}
     fullcopy1, fullcopy2 = {}, {}
     diverge = {}
 
@@ -351,7 +350,6 @@
         _checkcopies(c2, f, m2, m1, ca, limit, diverge, copy2, fullcopy2)
 
     copy = dict(copy1.items() + copy2.items())
-    movewithdir = dict(movewithdir1.items() + movewithdir2.items())
     fullcopy = dict(fullcopy1.items() + fullcopy2.items())
 
     renamedelete = {}
@@ -395,7 +393,7 @@
     del divergeset
 
     if not fullcopy:
-        return copy, movewithdir, diverge, renamedelete
+        return copy, {}, diverge, renamedelete
 
     repo.ui.debug("  checking for directory renames\n")
 
@@ -433,12 +431,13 @@
     del d1, d2, invalid
 
     if not dirmove:
-        return copy, movewithdir, diverge, renamedelete
+        return copy, {}, diverge, renamedelete
 
     for d in dirmove:
         repo.ui.debug("   discovered dir src: '%s' -> dst: '%s'\n" %
                       (d, dirmove[d]))
 
+    movewithdir = {}
     # check unaccounted nonoverlapping files against directory moves
     for f in u1r + u2r:
         if f not in fullcopy: