Fix compiler error

tools/dcdbslurmjob/dcdbslurmjob.cpp

@@ -353,7 +353,7 @@ int main(int argc, char** argv) {
             jd.jobId     = jobId;
             jd.userId    = userId;
             jd.startTime = DCDB::TimeStamp(ts);
-            jd.endTime   = (maxJobLength >= 0) ? DCDB::TimeStamp(ts + S_TO_NS(maxJobLength * 3600) + 1) : DCDB::TimeStamp((uint64_t)0);
+            jd.endTime   = (maxJobLength >= 0) ? DCDB::TimeStamp((uint64_t) (ts + S_TO_NS((uint64_t)maxJobLength * 3600ull) + 1)) : DCDB::TimeStamp((uint64_t)0);
             jd.nodes     = nl;
         } catch(const std::invalid_argument& e) {
 		std::cerr << "Invalid input format!" << std::endl;