Sort out signedness issues.

Windows is, not unreasonably, complaining that taking abs() of an unsigned is
ridiculous. But these values actually are signed and fit very easily in an int
anyway.

Change-Id: I34fecaaa3616732112e3eea105a7c84bd9cd0bae
Reviewed-on: https://boringssl-review.googlesource.com/8144
Reviewed-by: Adam Langley <agl@google.com>

crypto/newhope/newhope_statistical_test.cc

diff --git a/crypto/newhope/newhope_statistical_test.cc b/crypto/newhope/newhope_statistical_test.cc
index 1e2ad00..44fac48 100644
--- a/crypto/newhope/newhope_statistical_test.cc
+++ b/crypto/newhope/newhope_statistical_test.cc
@@ -75,7 +75,7 @@
   return true;
 }
 
-static int hamming32(const uint8_t key[NEWHOPE_KEY_LENGTH]) {
+static int Hamming32(const uint8_t key[NEWHOPE_KEY_LENGTH]) {
   static int kHamming[256] = {
     0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
     1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
@@ -112,7 +112,7 @@
       sp(NEWHOPE_POLY_new()), ep(NEWHOPE_POLY_new()), epp(NEWHOPE_POLY_new()),
       a(NEWHOPE_POLY_new()), bp(NEWHOPE_POLY_new()), rec(NEWHOPE_POLY_new());
 
-  uint64_t ones = 0;
+  int ones = 0;
   for (size_t i = 0; i < kNumTests; i++) {
     NEWHOPE_offer(offermsg, sk.get());
     NEWHOPE_offer_frommsg(pk.get(), a.get(), offermsg);
@@ -127,15 +127,15 @@
     NEWHOPE_accept_computation(key, bp.get(), rec.get(),
                                sp.get(), ep.get(), epp.get(), rand,
                                pk.get(), a.get());
-    ones += hamming32(key);
+    ones += Hamming32(key);
   }
 
-  uint64_t bits = NEWHOPE_KEY_LENGTH * 8 * kNumTests;
-  uint64_t diff = bits - 2 * ones;
+  int bits = NEWHOPE_KEY_LENGTH * 8 * kNumTests;
+  int diff = bits - 2 * ones;
   double fraction = (double) abs(diff) / bits;
-  printf("ones:   %u\n", (unsigned) ones);
-  printf("zeroes: %u\n", (unsigned) (bits - ones));
-  printf("diff:   got %u (%f), want %ld\n", (unsigned) diff, fraction, 0L);
+  printf("ones:   %d\n", ones);
+  printf("zeroes: %d\n", (bits - ones));
+  printf("diff:   got %d (%f), want 0\n", diff, fraction);
   printf("\n");
 
   if (fraction > 0.01) {