LU-9941 lov: lsm_is_composite isn't right

LU-9941 lov: lsm_is_composite isn't right

LOVEA magic containing LOV_MAGIC_MAGIC will also be regarded as
a composite magic.

Signed-off-by: Bobi Jam <bobijam.xu@intel.com>
Change-Id: I3ef37ee80364b2a8f27831e3c53fb88b464f2039
Reviewed-on: https://review.whamcloud.com/28845
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
(cherry picked from commit 385518f67eb917335de0c1d727941094f4ab5874)
Reviewed-on: https://review.whamcloud.com/30342
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>