don't leak on error path in Coin solver

Change-Id: Ice460975511dbdfcfcde9a829283d2abac14c263
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/115698
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

sccomp/source/solver/CoinMPSolver.cxx

@@ -326,6 +326,7 @@ void SAL_CALL CoinMPSolver::solve()
         }
         catch (const CoinError& e)
         {
+            CoinUnloadProblem(hProb);
             throw std::runtime_error(e.message());
         }
     }