always use /$cputype/bin/??? to find the correct plan9 command
when emulating [lu]nix commands in ape.

Reference: /n/sources/patch/maybe/ln.abs.paths
Date: Wed Nov 21 17:29:11 CET 2012
Signed-off-by: steve@quintile.net

--- /rc/bin/ape/ln	Wed Nov 21 17:28:17 2012
+++ /rc/bin/ape/ln	Wed Nov 21 17:28:14 2012
@@ -16,9 +16,9 @@
 }
 
 
-if(~ $force n && test -e $2 && ! test -d $2){
+if(~ $force n && /$cputype/bin/test -e $2 && ! test -d $2){
 	echo ln: $2 destination exists >[2=1]
 	exit 'usage'
 }
 
-exec cp -gux $1 $2
+exec /$cputype/bin/cp -gux $1 $2