plan9: mkfile and 9diff fixes

This patch deals with an unnecessary backslash in 9diff and improper
quoting in the contrib mkfile.

contrib/plan9/9diff

@@ -1,42 +1,42 b''
 #!/bin/rc
 # 9diff - Mercurial extdiff wrapper for diff(1)
 
 rfork e
 
 fn getfiles{
-	cd $1 && \
+	cd $1 &&
 	for(f in `{du -as | awk '{print $2}'})
 		test -f $f && echo `{cleanname $f}
 }
 
 fn usage{
 	echo >[1=2] usage: 9diff [diff options] parent child root
 	exit usage
 }
 
 opts=()
 while(~ $1 -*){
 	opts=($opts $1)
 	shift
 }
 if(! ~ $#* 3)
 	usage
 
 # extdiff will set the parent and child to a single file if there is
 # only one change. If there are multiple changes, directories will be
 # set. diff(1) does not cope particularly with directories; instead we
 # do the recursion ourselves and diff each file individually.
 if(test -f $1)
 	diff $opts $1 $2
 if not{
 	# extdiff will create a snapshot of the working copy to prevent
 	# conflicts during the diff. We circumvent this behavior by
 	# diffing against the repository root to produce plumbable
 	# output. This is antisocial.
 	for(f in `{sort -u <{getfiles $1} <{getfiles $2}}){
 		file1=$1/$f; test -f $file1 || file1=/dev/null
 		file2=$3/$f; test -f $file2 || file2=/dev/null
 		diff $opts $file1 $file2
 	}
 }
 exit ''

contrib/plan9/mkfile

@@ -1,37 +1,37 b''
 APE=/sys/src/ape
 <$APE/config
 
 PYTHON=python
 PYTHONBIN=/rc/bin
 SH=ape/psh
 
 PURE=--pure
 ROOT=../..
 
 # This is slightly underhanded; Plan 9 does not support GNU gettext nor
 # does it support dynamically loaded extension modules. We work around
 # this by calling build_py and build_scripts directly; this avoids
 # additional platform hacks in setup.py.
 build:VQ:
 	@{
 		cd $ROOT
 		$SH -c '$PYTHON setup.py $PURE build_py build_scripts'
 	}
 
 clean:VQ:
 	@{
 		cd $ROOT
 		$SH -c '$PYTHON setup.py $PURE clean --all'
 	}
 
 install:VQ:	build
 	@{
 		cd $ROOT
 		$SH -c '$PYTHON setup.py $PURE install \
 			--install-scripts $PYTHONBIN \
-			--skip-build' \
-			--force
+			--skip-build \
+			--force'
 	}
 	mkdir -p /lib/mercurial/hgrc.d
-	dircp hgrc.d /lib/mercurial/hgrc.d
-	cp 9diff /rc/bin
+	dircp hgrc.d /lib/mercurial/hgrc.d/
+	cp 9diff /rc/bin/