clang-tidy: drop redundant casts

Found via `readability-redundant-casting`. Prone to false positives, not
enabled.

Ref: https://clang.llvm.org/extra/clang-tidy/checks/readability/redundant-casting.html

Closes #20630

src/config2setopts.c

@@ -48,7 +48,7 @@ static int get_address_family(curl_socket_t sockfd)
   struct sockaddr addr;
   curl_socklen_t addrlen = sizeof(addr);
   memset(&addr, 0, sizeof(addr));
-  if(getsockname(sockfd, (struct sockaddr *)&addr, &addrlen) == 0)
+  if(getsockname(sockfd, &addr, &addrlen) == 0)
     return addr.sa_family;
   return AF_UNSPEC;
 }

src/tool_cb_hdr.c

@@ -432,7 +432,7 @@ size_t tool_header_cb(char *ptr, size_t size, size_t nmemb, void *userdata)
   struct OutStruct *etag_save = &per->etag_save;
   const char *str = ptr;
   const size_t cb = size * nmemb;
-  const char *end = (char *)ptr + cb;
+  const char *end = ptr + cb;
   const char *scheme = NULL;
 
   if(!per->config)

src/tool_cb_prg.c

@@ -113,7 +113,7 @@ static void update_width(struct ProgressData *bar)
   if(cols > MAX_BARLENGTH)
     bar->width = MAX_BARLENGTH;
   else if(cols > MIN_BARLENGTH)
-    bar->width = (int)cols;
+    bar->width = cols;
   else
     bar->width = MIN_BARLENGTH;
 }

src/tool_cb_rea.c

@@ -49,7 +49,7 @@ static bool waitfd(int waitms, int fd)
   set.fd = fd;
   set.events = POLLIN;
   set.revents = 0;
-  if(poll(&set, 1, (int)waitms))
+  if(poll(&set, 1, waitms))
     return TRUE; /* timeout */
   return FALSE;
 #else

src/tool_filetime.c

@@ -108,8 +108,7 @@ void setfiletime(curl_off_t filetime, const char *filename)
                            FILE_SHARE_READ | FILE_SHARE_WRITE |
                            FILE_SHARE_DELETE, NULL, OPEN_EXISTING, 0, NULL);
   if(hfile != INVALID_HANDLE_VALUE) {
-    curl_off_t converted = ((curl_off_t)filetime * 10000000) +
-      116444736000000000;
+    curl_off_t converted = (filetime * 10000000) + 116444736000000000;
     FILETIME ft;
     ft.dwLowDateTime = (DWORD)(converted & 0xFFFFFFFF);
     ft.dwHighDateTime = (DWORD)(converted >> 32);