Revert "[llvm-readobj/elf] - Refine the code for broken PT_DYNAMIC segment diagnostic."

This reverts commit 455d5a8a.

It broke UBSan:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/21386/steps/check-llvm%20ubsan/logs/stdio

/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/test/tools/llvm-readobj/ELF/malformed-pt-dynamic.test:62:10: error: WARN3: expected string not found in input
# WARN3: error: '[[FILE]]': Invalid data was encountered while parsing the file
         ^
<stdin>:2:1: note: scanning from here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
^
<stdin>:2:1: note: with "FILE" equal to "/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/test/tools/llvm-readobj/ELF/Output/malformed-pt-dynamic\\.test\\.tmp3"
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
^
<stdin>:2:117: note: possible intended match here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
                                                                                                                    ^
Input file: <stdin>
Check file: /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/test/tools/llvm-readobj/ELF/malformed-pt-dynamic.test