Older kernels do not support flush or trim operations; add #ifdefs to
allow the NBD test code to work on those kernels.
Fixes build on older distributions (e.g. CentOS 6).
Change-Id: Iae06f96b7db9a3bf4a494e2b2c2c15b37e6c1293
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/367132
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
dbbde9991d