Only mkdirp() the .redo directory in one place right at the beginning.

This doesn't really seem to change anything, but it's more correct and
should reveal weirdness (especially an incorrect .redo directory in a
sub-redo) sooner.

redo-ifcreate.py

@@ -10,7 +10,6 @@ if not vars.TARGET:
 
 try:
     for t in sys.argv[1:]:
-        mkdirp('%s/.redo' % vars.BASE)
         if os.path.exists(t):
             err('redo-ifcreate: error: %r already exists\n' % t)
             sys.exit(1)