s3/libsmb: Free memdup'd local variable

s3/libsmb: Free memdup'd local variable

secrets_fetch_machine_password() sets pwd to point to memdup()'d (and thus
malloc()'d) memory. This memory should be freed before we go out of scope.

Change-Id: I07e575819c309fa5b85627dce2eb969bc720ce4e
Coverity-Id: 1168001
Reviewed-by: Ira Cooper <ira@samba.org>
Signed-off-by: Jose A. Rivera <jarrpa@redhat.com>
Reviewed-by: Simo Sorce <idra@samba.org>
Autobuild-User(master): Simo Sorce <idra@samba.org>
Autobuild-Date(master): Sat Feb 22 00:58:23 CET 2014 on sn-devel-104