Duplicated "Entering/Leaving directory" when new option -O is used

[Stefano Lattarini]

Here is a minimal reproducer:

  $ cd /tmp
  $ mkdir x
  $ cd x
  $ mkdir src
  $ echo 'all:; $(MAKE) -C src $@' > Makefile
  $ echo 'all:; @echo src' > src/Makefile
  $ make # Work es expected
  make -C src all
  make[1]: Entering directory '/tmp/x/src'
  src
  make[1]: Leaving directory '/tmp/x/src'
  $ make -O # Duplicated lines in output
  make -C src all
  make[1]: Entering directory '/tmp/x/src'
  make[1]: Entering directory '/tmp/x/src'
  src
  make[1]: Leaving directory '/tmp/x/src'
  make[1]: Leaving directory '/tmp/x/src'

The above has been obtained with GNU make built from latest
git version (commit 'moved-to-git-46-g19a69ba').

Regards,
  Stefano