Fix test-sha256 build

wpa_supplicant/Makefile

@@ -1199,7 +1199,7 @@ test-sha1: $(TEST_SHA1_OBJS)
 	./test-sha1
 	rm test-sha1
 
-TEST_SHA256_OBJS = ../src/crypto/sha256.o ../src/crypto/md5.o tests/test_sha256.o ../src/crypto/crypto_openssl.o
+TEST_SHA256_OBJS = ../src/crypto/sha256.o ../src/crypto/md5.o tests/test_sha256.o ../src/utils/os_unix.o ../src/crypto/crypto_openssl.o
 test-sha256: $(TEST_SHA256_OBJS)
 	$(LDO) $(LDFLAGS) -o $@ $(TEST_SHA256_OBJS) $(LIBS)
 	./test-sha256

wpa_supplicant/tests/test_sha256.c

@@ -323,7 +323,8 @@ int main(int argc, char *argv[])
 	}
 
 	printf("Test IEEE 802.11r KDF\n");
-	sha256_prf("abc", 3, "KDF test", "data", 4, hash, sizeof(hash));
+	sha256_prf((u8 *) "abc", 3, "KDF test", (u8 *) "data", 4,
+		   hash, sizeof(hash));
 	/* TODO: add proper test case for this */
 
 	return errors;