recovery: fix --update_package using legacy path

When using legacy path, recovery will not be able to mount the
correct device. Fix by resolving the symlink before installing.

Change-Id: Ibb268908458c49de09204a1a0ba3143e83ccc0c4
Merge "recovery: fix --update_package using legacy path" into cm-10.2
Revert "recovery: fix --update_package using legacy path"

This reverts commit 9a490c1bd370affe352915e0b2b36c4af5b88955.
Merge remote-tracking branch 'github/cm-10.2' into mackay-cm102