tests: comparators: test_rlib: fixes llvm >= 5.0 test case

Due to LLVM changes in version 5.0, our expected diff wasn't matching
LLVMs output. /test_item3_deflate_llvm_bitcode/ had its expectations
updated.

Closes: #877727

Signed-off-by: Juliana Oliveira Rodrigues <juliana.orod@gmail.com>