log: do not use exact matcher for --patch --follow without file (
issue4319)
e2530d4a47c1 is valid only if file argument is specified. If no pattern
specified, it can simply fall back to the original matcher.
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ hg qsave
$ hg qrestore 2
restoring status: hg patches saved state