ocfs2-devel: remove redundant OCFS2_MOUNT_POSIX_ACL check in ocfs2_get_acl_nolock()

osb->s_mount_opt has already been checked against OCFS2_MOUNT_POSIX_ACL_CHECK before
calling ocfs2_get_acl_nolock() in ocfs2_init_acl() && ocfs2_get_acl(), so remove it.

Signed-off-by: Jeff Liu <jeff.liu@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>