[llvm-objdump] Move --start-address >= --stop-address check out of the

-d code.

Summary:
Move it into `main` function so the checking is effective for all actions
user may do with llvm-objdump; notably, -r and -s in addition to existing -d.

Match GNU behavior.

Reviewers: jhenderson, grimar, MaskRay, rupprecht

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63631

llvm-svn: 364118