Fix bin_elf import & symbol leak

[kazarmy]

Your checklist for this pull request

• I've read the guidelines for contributing to this repository
• I made sure to follow the project's coding style
• I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

This pr fixes the bin_elf import and symbol leak.

Test plan

All builds are green.

Closing issues

...

[kazarmy]

The original code doesn't do any freeing in rz_bin_reloc_free() -- the pr code does, and so despite the leaks this pr is an improvement.

[wargio]

as long as it doesn't double free, it is ok for me

[XVilka]

@kazarmy @wargio it broke a lot of fuzzy tests https://github.com/rizinorg/rizin/actions/runs/9139434697/job/25131720267#step:21:23