container/bits: move bind bits

This allows referring to the bits without importing container.

Signed-off-by: Ophestra <cat@gensokyo.uk>

system/dbus/proc.go

@@ -114,7 +114,7 @@ func (p *Proxy) Start() error {
 				check.SortAbs(sockDirPaths)
 				sockDirPaths = check.CompactAbs(sockDirPaths)
 				for _, name := range sockDirPaths {
-					z.Bind(name, name, container.BindWritable)
+					z.Bind(name, name, bits.BindWritable)
 				}
 
 				// xdg-dbus-proxy bin path