[CIFS] Remove duplicate call to mode_to_acl

The current logic in cifs_setattr calls mode_to_acl twice on mode
changes if cifsacl is enabled. Remove the duplicate call.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>