Some fuzzer workarounds

[Evgeny Vereshchagin]

Hi,

> I looked over the "ClusterFuzz-External via monorail" emails and found
> some "real" issues.

Given that the new fuzz targets seem to just fail to compile with
```
projects/elfutils/fuzz-libdwfl.c:48:10: error: unused variable 'res' [-Werror,-Wunused-variable]
  Dwarf *res = dwfl_module_getdwarf(mod, &bias);
         ^
1 error generated.
```
I think before looking at those reports it would make sense to figure out what they are supposed to
test and how they were tested to make sure they don't produce false positives. If they
weren't actually tested I think it would make sense to revert them to avoid getting auto-generated CVEs
until they're in more or less good shape at least.

> There are also some other
> misaligned type access checks reported by ubsan, but I don't know if
> that is because of ALLOW_UNALIGNED is still defined or not (when
> configuring with --enable-analyze-undefined ALLOW_UNALIGNED is not
> defined, otherwise it is for some arches, including x86_64).

Looking at https://github.com/google/oss-fuzz/commit/8747524f04b1b906d4a21a6ade87f7803b3f9b8c, I think
I turned ALLOW_UNALIGNED off with UBSan there (and tested it in https://sourceware.org/bugzilla/show_bug.cgi?id=28720).

Thanks,
Evgeny Vereshchagin