Fix NTLM winbind support to pass the torture tests

Calling sclose() both in the child and the parent fools the
socket leak detector into thinking it's been closed twice.
Calling close() in the child instead overcomes this problem. It's
not as portable as the sclose() macro, but this code is highly
POSIX-specific, anyway.

lib/curl_ntlm_wb.c

@@ -166,8 +166,8 @@ static CURLcode ntlm_wb_init(struct connectdata *conn, const char *userp)
      * child process
      */
 
-    sclose(sockfds[0]);
-
+    /* Don't use sclose in the child since it fools the socket leak detector */
+    close(sockfds[0]);
     if(dup2(sockfds[1], STDIN_FILENO) == -1) {
       error = ERRNO;
       failf(conn->data, "Could not redirect child stdin. errno %d: %s",
@@ -197,7 +197,7 @@ static CURLcode ntlm_wb_init(struct connectdata *conn, const char *userp)
             NULL);
 
     error = ERRNO;
-    sclose(sockfds[1]);
+    close(sockfds[1]);
     failf(conn->data, "Could not execl(). errno %d: %s",
           error, Curl_strerror(conn, error));
     exit(1);