vendor/lineage: Support relative OUT_DIR in fixup_common_out_dir

* For use with LINEAGE_FIXUP_COMMON_OUT=1, update
  symlink handling to work with relative OUT_DIR.

* Fixes error:
FAILED: ninja: error: mkdir(out/target/common/obj): No such file or directory

Change-Id: I958be470b4d9ff2074442f210b1a73541e4981c8
1 file changed