drm/asahi: mmu: Change step_remap() to new api

Signed-off-by: Asahi Lina <lina@asahilina.net>

Author: hoshinolina

drivers/gpu/drm/asahi/mmu.rs

@@ -231,8 +231,6 @@ struct StepContext {
     prev_va: Option<Pin<KBox<gpuvm::GpuVa<VmInner>>>>,
     next_va: Option<Pin<KBox<gpuvm::GpuVa<VmInner>>>>,
     vm_bo: Option<ARef<gpuvm::GpuVmBo<VmInner>>>,
-    prev_vm_bo_1: Option<ARef<gpuvm::GpuVmBo<VmInner>>>,
-    prev_vm_bo_2: Option<ARef<gpuvm::GpuVmBo<VmInner>>>,
     prot: u32,
 }
 
@@ -414,17 +412,6 @@ impl gpuvm::DriverGpuVm for VmInner {
             }
         }
 
-        if ctx.prev_vm_bo_1.is_none() {
-            assert!(ctx.prev_vm_bo_1.replace(vm_bo).is_none());
-        } else if ctx.prev_vm_bo_2.is_none() {
-            assert!(ctx.prev_vm_bo_2.replace(vm_bo).is_none());
-        } else {
-            dev_crit!(
-                self.dev.as_ref(),
-                "step_remap: too many remap ops, deadlock expected"
-            );
-        }
-
         Ok(())
     }
 }