Prototype fixes for pardiso

[bnaras]

The R interface required these prototype fixes (among a few others) as CRAN enables prototype checks. Reference: https://discourse.llvm.org/t/rfc-enabling-wstrict-prototypes-by-default-in-c/60521/20

The fixes here are very trivial.

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[coveralls]

Pull Request Test Coverage Report for Build 3432777756

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 91.033%

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Totals
Change from base Build 3070562604:	0.0%
Covered Lines:	1868
Relevant Lines:	2052

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💛 - Coveralls

[imciner2]

@vineetbansal the MKL tests for master seem to be having trouble loading the library now. The master branch still loads MKL manually, so it looks in a few places, the error it gives is:

ERROR in lh_load_lib: Error while loading dynamic library libmkl_rt.dylib: dlopen(libmkl_rt.dylib, 0x0001): tried: 'libmkl_rt.dylib' (no such file), '/usr/local/lib/libmkl_rt.dylib' (no such file), '/usr/lib/libmkl_rt.dylib' (no such file), '/Users/runner/work/osqp/osqp/libmkl_rt.dylib' (no such file)

Does conda install the library in any of those places, or is there somewhere else it puts it?

[bnaras]

Can this PR be acted upon? Else I am forced to keep patching up the R interface indefinitely! Thank you.

[vineetbansal]

Hi @bnaras, @imciner2 - I'm merging this PR because the changes are trivial and correct. What was holding this PR back was failing tests on macos-latest, for which there is a dedicated PR #490. I'll keep that open.