build: fix Codacy/CppCheck warnings

- remove unused variables
- declare conditionally used variables conditionally
- suppress unused variable warnings in the CMake tests
- remove dead variable stores
- consistently use WIN32 macro to detect Windows

Closes https://github.com/curl/curl/pull/3739

1 files changed, 3 insertions, 1 deletions

diff --git a/tests/libtest/lib1522.c b/tests/libtest/lib1522.c
index 2de955284..6ac2f9358 100644
--- a/tests/libtest/lib1522.c
+++ b/tests/libtest/lib1522.c
@@ -32,14 +32,16 @@ static char g_Data[40 * 1024]; /* POST 40KB */
 static int sockopt_callback(void *clientp, curl_socket_t curlfd,
                             curlsocktype purpose)
 {
+#if defined(SOL_SOCKET) && defined(SO_SNDBUF)
   int sndbufsize = 4 * 1024; /* 4KB send buffer */
   (void) clientp;
   (void) purpose;
-#if defined(SOL_SOCKET) && defined(SO_SNDBUF)
   setsockopt(curlfd, SOL_SOCKET, SO_SNDBUF,
              (const char *)&sndbufsize, sizeof(sndbufsize));
 #else
+  (void)clientp;
   (void)curlfd;
+  (void)purpose;
 #endif
   return CURL_SOCKOPT_OK;
 }