CDRIVER-2875 bug fix for FD_CLOEXEC

Author: kevinAlbs

src/libmongoc/src/mongoc/mongoc-socket.c

@@ -102,12 +102,17 @@ _mongoc_socket_setflags (int sd)
 
    flags = fcntl (sd, F_GETFL, sd);
 
+   if (-1 == fcntl (sd, F_SETFL, (flags | O_NONBLOCK))) {
+      return false;
+   }
+
 #ifdef FD_CLOEXEC
-   return (-1 != fcntl (sd, F_SETFL, (flags | O_NONBLOCK | FD_CLOEXEC)));
-#else
-   return (-1 != fcntl (sd, F_SETFL, (flags | O_NONBLOCK)));
+   flags = fcntl (sd, F_GETFD, sd);
+   if (-1 == fcntl (sd, F_SETFD, (flags | FD_CLOEXEC))) {
+      return false;
+   }
 #endif
-
+   return true;
 #endif
 }