drm/xe: Fix lockdep warning from xe_vm_madvise

We need to hold vm->lock before the xe_vm_is_closed_or_banned().

Else we get this splat:
[  802.555227] ------------[ cut here ]------------
[  802.555234] WARNING: CPU: 33 PID: 3122 at drivers/gpu/drm/xe/xe_vm.h:60
[  802.555515] CPU: 33 PID: 3122 Comm: xe_exec_fault_m Tainted:
...
[  802.555709] Call Trace:
[  802.555714]  <TASK>
[  802.555720]  ? __warn+0x81/0x170
[  802.555737]  ? xe_vm_madvise_ioctl+0x2de/0x440 [xe]

Fixes: 9d858b69 ("drm/xe: Ban a VM if rebind worker hits an error")
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Brian Welty <brian.welty@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_vm_madvise.c

@@ -267,11 +267,6 @@ int xe_vm_madvise_ioctl(struct drm_device *dev, void *data,
 	if (XE_IOCTL_ERR(xe, !vm))
 		return -EINVAL;
 
-	if (XE_IOCTL_ERR(xe, xe_vm_is_closed_or_banned(vm))) {
-		err = -ENOENT;
-		goto put_vm;
-	}
-
 	if (XE_IOCTL_ERR(xe, !xe_vm_in_fault_mode(vm))) {
 		err = -EINVAL;
 		goto put_vm;
@@ -279,6 +274,11 @@ int xe_vm_madvise_ioctl(struct drm_device *dev, void *data,
 
 	down_read(&vm->lock);
 
+	if (XE_IOCTL_ERR(xe, xe_vm_is_closed_or_banned(vm))) {
+		err = -ENOENT;
+		goto unlock_vm;
+	}
+
 	vmas = get_vmas(vm, &num_vmas, args->addr, args->range);
 	if (XE_IOCTL_ERR(xe, err))
 		goto unlock_vm;