If checkit is passed a 4th arg, skip the file-diffing step.

This is used by the devices.test script.

testsuite/rsync.fns

@@ -165,17 +165,23 @@ checkit() {
 	failed="YES";
     fi
 
-    echo "-------------"
-    echo "check how the files compare with diff:"
-    echo ""
-    diff -r $diffopt "$2" "$3" || failed=YES
-
     echo "-------------"
     echo "check how the directory listings compare with diff:"
     echo ""
     ( cd "$2" && rsync_ls_lR . ) > "$tmpdir/ls-from"
     ( cd "$3" && rsync_ls_lR . ) > "$tmpdir/ls-to"
     diff $diffopt "$tmpdir/ls-from" "$tmpdir/ls-to" || failed=YES
+
+    echo "-------------"
+    echo "check how the files compare with diff:"
+    echo ""
+    if [ "x$4" != x ]; then
+	echo "  === Skipping (as directed) ==="
+    else
+	diff -r $diffopt "$2" "$3" || failed=YES
+    fi
+
+    echo "-------------"
     if [ -z "$failed" ] ; then
 	return 0
     else