Fix absolute path to `cat'.

--- mailutils-2.2/testsuite/lib/mailutils.exp	2010-09-10 13:39:58.000000000 +0200
+++ mailutils-2.2/testsuite/lib/mailutils.exp	2010-09-10 13:40:00.000000000 +0200
@@ -719,7 +719,7 @@ proc mu_test_file {args} {
         set pattern [lrange $args 1 end]
     }
     
-    set res [remote_spawn host "/bin/cat $filename"]
+    set res [remote_spawn host "cat $filename"]
     if { $res < 0 || $res == "" } {
 	perror "Reading $filename failed."
 	return 1;