pgbench: Make set_random_seed() 64-bit everywhere.

Delete an intermediate variable, a redundant cast, a use of long and a
use of long long.  scanf() the seed directly into a uint64, now that we
can do that with SCNu64 from <inttypes.h>.

The previous coding was from pre-C99 times when %lld might not have been
there, so it read into an unsigned long.  Therefore behavior varied
by OS, and --random-seed would accept either 32 or 64 bit seeds.  Now
it's the same everywhere.

Author: macdice

src/bin/pgbench/pgbench.c

@@ -6639,27 +6639,23 @@ set_random_seed(const char *seed)
 	}
 	else
 	{
-		/* parse unsigned-int seed value */
-		unsigned long ulseed;
 		char		garbage;
 
-		/* Don't try to use UINT64_FORMAT here; it might not work for sscanf */
-		if (sscanf(seed, "%lu%c", &ulseed, &garbage) != 1)
+		if (sscanf(seed, "%" SCNu64 "%c", &iseed, &garbage) != 1)
 		{
 			pg_log_error("unrecognized random seed option \"%s\"", seed);
 			pg_log_error_detail("Expecting an unsigned integer, \"time\" or \"rand\".");
 			return false;
 		}
-		iseed = (uint64) ulseed;
 	}
 
 	if (seed != NULL)
-		pg_log_info("setting random seed to %llu", (unsigned long long) iseed);
+		pg_log_info("setting random seed to %" PRIu64, iseed);
 
 	random_seed = iseed;
 
 	/* Initialize base_random_sequence using seed */
-	pg_prng_seed(&base_random_sequence, (uint64) iseed);
+	pg_prng_seed(&base_random_sequence, iseed);
 
 	return true;
 }