Fix windows-specific error without messing up Makefile flags.

Bug: 14416410

The proper fix for the error/warning we encountered is to move winsock2.h
in front of windows.h.

Change-Id: I29504ba3a184a85c6636d06c2ad900828fdb5436
diff --git a/adb/usb_windows.c b/adb/usb_windows.c
index 1309a78..b7ad913 100644
--- a/adb/usb_windows.c
+++ b/adb/usb_windows.c
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <winsock2.h>
 #include <windows.h>
 #include <winerror.h>
 #include <errno.h>