prebuilt: allow user to move binaries to /vendor/bin/hw in ramdisk

Change-Id: Id6c17f2efcb1490d473311f3aa61ba3d652c6607
diff --git a/prebuilt/relink.sh b/prebuilt/relink.sh
index 063f445..5917114 100755
--- a/prebuilt/relink.sh
+++ b/prebuilt/relink.sh
@@ -12,6 +12,7 @@
       src=$2.tmp
     fi
 
+    mkdir -p $1
     cp $src $dst
     if [[ -e $2.tmp ]]; then rm -f $2.tmp; fi
 }