Fix at-exit leak in eratosthenes program.

ChangeLog

 2018-07-12  Niels Möller  <nisse@lysator.liu.se>
 
+	* examples/eratosthenes.c (main): Don't allocate bitmap storage
+	for limit == 2 (early exit), closing memory leak at exit.
+
 	* eccdata.c (output_curve): Replace mpz_init_set_ui by mpz_set_ui,
 	to fix memory leak.
 	(ecc_curve_clear): New function.

examples/eratosthenes.c

@@ -314,8 +314,6 @@ main (int argc, char **argv)
   root = (root - 1) | 1;
   /* Represents odd numbers from 3 up. */
   sieve_nbits = (root - 1) / 2;
-  sieve = vector_alloc(sieve_nbits );
-  vector_init(sieve, sieve_nbits);
 
   if (verbose)
     fprintf(stderr, "Initial sieve using %lu bits.\n", sieve_nbits);
@@ -326,6 +324,9 @@ main (int argc, char **argv)
   if (limit == 2)
     return EXIT_SUCCESS;
 
+  sieve = vector_alloc(sieve_nbits);
+  vector_init(sieve, sieve_nbits);
+
   for (bit = 0;
        bit < sieve_nbits;
        bit = vector_find_next(sieve, bit + 1, sieve_nbits))