r24637: In order for "net rpc registry" to be able to write to

r24637: In order for "net rpc registry" to be able to write to
Samba's own registry, the access mask for opening the
registry for the write operations needs to be
SEC_RIGHTS_MAXIMUM_ALLOWED instead of REG_WRITE: we can
not open e.g. HKLM read write explicitly, since we can
not write to this virtual part of the registry, only
to the subkeys like 'HKLM\Software\Samba\smbconf' that
are stored on disk.

Note that MAXIMUM_ALLOWED is also what windows' regedit
passed to the open calls.

Michael