nvhw/pgraph_celsius: Fix rcp(-0).
nvhw/pgraph_celsius: Fix rcp(-0).

karolherbst/envytools,pierremoreau/envytools,karolherbst/envytools,envytools/envytools,karolherbst/envytools,envytools/envytools,envytools/envytools,envytools/envytools,karolherbst/envytools,pierremoreau/envytools,pierremoreau/envytools,karolherbst/envytools,pierremoreau/envytools,pierremoreau/envytools,envytools/envytools