LU-5062 llite: Solve a race to access lli_has_smd in read case

LU-5062 llite: Solve a race to access lli_has_smd in read case

In vvp_io_read_lock(), it used to decide if to add read lock by
checking lli_has_smd. Accessing lli_has_smd is racy when an empty
file is turned into raid0, therefore, it may result in read requests
are issued without corresponding lock.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: I70cb1888b42e0e9928f8346359e2b1f554fe4e8f
Reviewed-on: http://review.whamcloud.com/10760
Tested-by: Jenkins
Reviewed-by: Patrick Farrell <paf@cray.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bobi Jam <bobijam@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>