randomtest fixes

diff --git a/scripts/randomtest b/scripts/randomtest
index d9d3959..7b80f4a 100755
--- a/scripts/randomtest
+++ b/scripts/randomtest
@@ -90,7 +90,7 @@
 # Regenerate .config with default answers for yanked-off options
 { yes "" | make oldconfig >/dev/null; } || exit 1
 
-nice -n 10 make
+nice -n 10 make 2>&1 | tee -a make.log
 
 test -x busybox && {
     cd ..
@@ -99,5 +99,5 @@
 }
 
 cd ..
-mv "$dir" failed."$dir"
+mv "$dir" "failed.$dir"
 exit 1