[bolt] Fix a test affected by D131589.

This test contained some data tables that llvm-objdump was
disassembling as code, so the test was recovering the 32-bit values in
the table from the instruction encoding column of the disassembly.

D131589 changed how llvm-objdump decides what to disassemble as code
or as data. As a result, these data tables are now being disassembled
as data, which I think is actually more sensible -- but the test
wasn't expecting it, and got confused.