sheepdog: remove unnecessary includes

"qemu_socket.h" includes all necessary files and
including <netinet/tcp.h> without <netinet/in.h>
could cause errors on some systems.

Signed-off-by: Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/sheepdog.c

@@ -8,16 +8,6 @@
  * You should have received a copy of the GNU General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
-#ifdef _WIN32
-#include <windows.h>
-#include <winsock2.h>
-#include <ws2tcpip.h>
-#else
-#include <netdb.h>
-#include <netinet/tcp.h>
-
-#define closesocket(s) close(s)
-#endif
 
 #include "qemu-common.h"
 #include "qemu-error.h"