xenstored: support for tdb_copy with TDB_INTERNAL

xenstored: support for tdb_copy with TDB_INTERNAL

The tdb_copy function should honor the TDB_INTERNAL flag for in-memory
databases; this is required to run in mini-os which does not use a
filesystem.

Signed-off-by: Diego Ongaro <diego.ongaro@citrix.com>
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>