firmware: prevent ChromeOS from booting with Tianocore as RWL

Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>

firmware.sh

@@ -142,6 +142,9 @@ else
   echo_green "RW_LEGACY firmware successfully installed/updated."
   # update firmware type
   firmwareType="Stock ChromeOS w/RW_LEGACY"
+  #Prevent from trying to boot stock ChromeOS install
+  rm -rf /tmp/boot/efi > /dev/null 2>&1
+  rm -rf /tmp/boot/syslinux > /dev/null 2>&1
 fi
 
 if [ -z "$1" ]; then