gpu.c: create_sync_leaf: pass ppcg_kernel pointer instead of gpu_gen pointer
gpu.c: create_sync_leaf: pass ppcg_kernel pointer instead of gpu_gen pointer

The only information we need from the gpu_gen structure is exactly
this ppcg_kernel pointer.

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

Meinersbur/ppcg,nicolasvasilache/ppcg,nicolasvasilache/ppcg,Meinersbur/ppcg