local.conf: Disable prelinking

:Release Notes:
Remove "image-prelink" from USER_CLASSES in local-conf.in . Must
invoke ./mcf.status in order for this change to take effect.

:Detailed Notes:

:Testing Performed:
Examined the log.do_rootfs of a local build and confirmed that the
usual output from the prelinking step was not present.

:QA Notes:

:Build Notes:
Invalidates shared state.

:Issues Addressed:
[ES-758]   Disable prelinking when building images
[BHV-7420] CCC: Disable prelinking when building images

Open-webOS-DCO-1.0-Signed-off-by: Herb Kuta <herb.kuta@lge.com>
Change-Id: Id0a1527c6fc4547090bb89d5b1897fc86b5f79d5
Reviewed-on: https://g2g.palm.com/5612
Reviewed-by: DCO Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Tested-by: Susan Montooth <susan.montooth@lge.com>