scsi: increase max lun name length

This patch increases maximum length of lun name.
16 was not long enough considering that lvol names can get
up to 48 (lvs uuid + lvol id).

Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Change-Id: Ic3557a9b3588f8d87f4188ecfaef7d23016a3516
Reviewed-on: https://review.gerrithub.io/377345


Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>