randomtest fixes

scripts/randomtest

@@ -90,7 +90,7 @@ mv .config.new .config
 # 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 @@ test -x busybox && {
 }
 
 cd ..
-mv "$dir" failed."$dir"
+mv "$dir" "failed.$dir"
 exit 1