FmpDevicePkg FmpDxe: Return 0 when LSV check is not required

Current code return 1 when LSV check is not required,
but 1 LSV will make 0 Version capsule image update failed.

0 LSV is valid, this patch updates the code to return 0 when
LSV check is not required
We can see even the DEFAULT_LOWESTSUPPORTEDVERSION is 0.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>