test: mark iscsi_initiator.sh as executable

This fixes check_format.sh error.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I3748ce34b339a4b2e0a8358d38a68f0520177384

Reviewed-on: https://review.gerrithub.io/437875


Reviewed-by: Seth Howell <seth.howell5141@gmail.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>