Fixup AVR tests to reflect changes in addend format in llvm-objdump

Summary: Changes to llvm-objdump made in D69997

Reviewers: thakis, jhenderson, grimar

Reviewed By: thakis

Subscribers: dylanmckay, Jim, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70438