Remove unused code for patching oat files.

patchoat is now only used for patching images. It no longer needs to
support patching of non-PIC oat files. This change removes code from
patchoat that was specific to patching of non-PIC oat files.

Bug: 33192586
Test: m test-art-host
Test: device boots
Change-Id: I8918a708e441493a21f25d537ed0b74748bb9641
4 files changed