Fix compiler warnings

src/miner.cpp

@@ -1277,7 +1277,7 @@ void static RandomXMiner()
                     rxdebug("%s: Checking solution against target\n");
                     pblock->nSolution = soln;
                     solutionTargetChecks.increment();
-                    rxdebug("%s: solutionTargetChecks=%d\n", solutionTargetChecks.get());
+                    fprintf(stderr,"%s: solutionTargetChecks=%lu\n", __func__, solutionTargetChecks.get());
                     B = *pblock;
                     h = UintToArith256(B.GetHash());
 
@@ -1646,6 +1646,7 @@ void static BitcoinMiner()
                     LogPrint("pow", "- Checking solution against target\n");
                     pblock->nSolution = soln;
                     solutionTargetChecks.increment();
+                    rxdebug("%s: solutionTargetChecks=%lu\n", solutionTargetChecks.get());
                     B = *pblock;
                     h = UintToArith256(B.GetHash());
                     /*for (z=31; z>=16; z--)