Replace winapi GetQueuedCompletionStatus bind with x/sys/windows

Previously we had our own definition for GetQueuedCompletionStatus as x/sys/windows
had an incorrect definition for it. This was remedied a bit ago in this change
golang/sys@683adc9
so we're alright to remove our own at this point.

Signed-off-by: Daniel Canter <dcanter@microsoft.com>

internal/jobobject/iocp.go

@@ -38,7 +38,7 @@ func pollIOCP(ctx context.Context, iocpHandle windows.Handle) {
 	)
 
 	for {
-		err := winapi.GetQueuedCompletionStatus(iocpHandle, &code, &key, (**windows.Overlapped)(unsafe.Pointer(&overlapped)), windows.INFINITE)
+		err := windows.GetQueuedCompletionStatus(iocpHandle, &code, &key, (**windows.Overlapped)(unsafe.Pointer(&overlapped)), windows.INFINITE)
 		if err != nil {
 			log.G(ctx).WithError(err).Error("failed to poll for job object message")
 			continue

internal/winapi/winapi.go

@@ -2,4 +2,4 @@
 // be thought of as an extension to golang.org/x/sys/windows.
 package winapi
 
-//go:generate go run ..\..\mksyscall_windows.go -output zsyscall_windows.go user.go console.go system.go net.go path.go thread.go iocp.go jobobject.go logon.go memory.go process.go processor.go devices.go filesystem.go errors.go
+//go:generate go run ..\..\mksyscall_windows.go -output zsyscall_windows.go user.go console.go system.go net.go path.go thread.go jobobject.go logon.go memory.go process.go processor.go devices.go filesystem.go errors.go