ART: Better error reporting on broken oat file

Do not blow up when in GetHashBucket if GetHashBucketNum is zero.
Instead back-step to ElfFileOpen, which prints which symbol was
missing from which file.

Bug: 17422404

(cherry picked from commit 1b2140c9)

Change-Id: I3b890dd1c31c08b1ccc0f7f668afcceee95f8d00