[llvm-objcopy][MachO] Ignore LC_LINKER_OPTION when redefining symbols

Previously you would get this error:

```
error: unsupported load command (cmd=0x2d)
```

If the binary you were redefining the symbols of contained a
LC_LINKER_OPTION load command. This command does not need to be changed
when redefining symbols so we can ignore it like many others.

Differential Revision: https://reviews.llvm.org/D118526