Fix comparison test in hash_equal, release 1.0.1.

The result in the loop was being reset each iteration; only the last
element in the byte array was being checked for equality.

src/emsha.cc

@@ -55,7 +55,7 @@ hash_equal(const uint8_t *a, const uint8_t *b)
 	EMSHA_CHECK(b != NULL, false);
 
 	for (uint32_t i = 0; i < SHA256_HASH_SIZE; i++) {
-		res = a[i] ^ b[i];
+		res += a[i] ^ b[i];
 	}
 
 	return res == 0;