switch to go vendoring

vendor/github.com/ceph/go-ceph/internal/cutil/sync_buffer.go

@@ -0,0 +1,29 @@
+//go:build !no_ptrguard
+// +build !no_ptrguard
+
+package cutil
+
+import (
+	"unsafe"
+)
+
+// SyncBuffer is a C buffer connected to a data slice
+type SyncBuffer struct {
+	pg *PtrGuard
+}
+
+// NewSyncBuffer creates a C buffer from a data slice and stores it at CPtr
+func NewSyncBuffer(cPtr CPtr, data []byte) *SyncBuffer {
+	var v SyncBuffer
+	v.pg = NewPtrGuard(cPtr, unsafe.Pointer(&data[0]))
+	return &v
+}
+
+// Release releases the C buffer and nulls its stored pointer
+func (v *SyncBuffer) Release() {
+	v.pg.Release()
+}
+
+// Sync asserts that changes in the C buffer are available in the data
+// slice
+func (*SyncBuffer) Sync() {}