Removed prebuilt kernel copy line

Change-Id: I14e4f91488422ac6c4b11d00057713f068cfc205
hammerhead: TWRP-ify
Finalize the TWRP-ify

Copy the twrp.fstab to the recovery ramdisk

Change-Id: I8c39f1dde79a1005079f1dd2c41163efde5bf353