s3:smb2_create: fix allocation size return value when opening existing files
at least on GPFS, using the stat information gave wrong results
example: FileInfo gave
12582912000, Create Response gave
25769803776000
This makes the create part use the same method as fileinfo,
matching up the replies of both calls
Autobuild-User: Jeremy Allison <jra@samba.org>
Autobuild-Date: Mon Oct 10 21:49:53 CEST 2011 on sn-devel-104
(cherry picked from commit
ec0c1f2c34ea520b4a7d636ba284a9c7d3ecd96f)
Fix bug #8518 (SMB2 create call returns incorrect file allocation size).