FSkeletalMeshMerge::CalculateLodCount calculates minimum LODs improperly

CalculateLodCount tries to bound the output LOD count as at least one (count >= 1), but actually bounds it as no more than 1 (count <= 1).

Just need to change a FMath::Min to FMath::Max.

1. Perform a skeletal mesh merge where each mesh list has multiple LODs.
2. Inspect the number of LODs for the resultant mesh.

Expected: The number of LODs should be the same as the mesh with the least number of LODs.

Actual: The number of LODs is always 1.