cifs: setcifsacl - Send the actual (security descriptor) buffer size instead of the...

cifs: setcifsacl - Send the actual (security descriptor) buffer size instead of the pre-allocated size

Some SMB servers such as HDS HNAS (Hitachi NAS) return error
NT Status: STATUS_INVALID_SECURITY_DESCR (0xc0000079)
during set cifs acl operation.

This happens due to mismatch in the size of actual security descriptor
being set versus the size of the security descriptor stated in the request.

Instead of sending allocated buffer size of a security descriptor,
send the actual size of the security descriptor during set cifs acl
operation.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>