The device general capability has a bit that indicate whether 'block on
fault' is supported. Add check to wq sysfs knob to check if cap exists
before allowing user to toggle.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162802992615.3084999.12539468940404102898.stgit@djiang5-desk3.ch.intel.comSigned-off-by: NVinod Koul <vkoul@kernel.org>