etnaviv: Fix memory leak in etna_vertex_elements_state_create.

Fix defect reported by Coverity Scan.

Resource leak (RESOURCE_LEAK) leaked_storage: Variable cs going out of scope leaks the storage it points to.

Fixes: c9e8b49b ("etnaviv: gallium driver for Vivante GPUs") Signed-off-by: Vinson Lee vlee@freedesktop.org