drm: Uncomment checks on oops_in_progress

[Why]
Usually, these correspond to functions which must be aborted when there
is a panic in progress.

`oops_in_progress` is supported by linuxkpi, thus we can rely on it.

This should fix nested panics I saw because the some code verifies that
some locks were acquires but they were not (because they were correctly
skipped inside a panic). These lock assertions would cause another panic
on top of the one being processed.

[How]
We simply remove all the `#ifdef __FreeBSD__`.

drivers/gpu/drm/drm_modeset_lock.c

@@ -138,10 +138,8 @@ void drm_modeset_lock_all(struct drm_device *dev)
 	struct drm_modeset_acquire_ctx *ctx;
 	int ret;
 
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return;
-#endif
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL);
 	if (WARN_ON(!ctx))
@@ -196,10 +194,8 @@ void drm_modeset_unlock_all(struct drm_device *dev)
 	struct drm_mode_config *config = &dev->mode_config;
 	struct drm_modeset_acquire_ctx *ctx = config->acquire_ctx;
 
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return;
-#endif
 
 	if (WARN_ON(!ctx))
 		return;
@@ -225,10 +221,8 @@ void drm_warn_on_modeset_not_all_locked(struct drm_device *dev)
 	struct drm_crtc *crtc;
 
 	/* Locking is currently fubar in the panic handler. */
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return;
-#endif
 
 	drm_for_each_crtc(crtc, dev)
 		WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
@@ -250,10 +244,8 @@ EXPORT_SYMBOL(drm_warn_on_modeset_not_all_locked);
 void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx,
 		uint32_t flags)
 {
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return;
-#endif
 
 	memset(ctx, 0, sizeof(*ctx));
 	ww_acquire_init(&ctx->ww_ctx, &crtc_ww_class);
@@ -270,10 +262,8 @@ EXPORT_SYMBOL(drm_modeset_acquire_init);
  */
 void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx)
 {
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return;
-#endif
 
 	ww_acquire_fini(&ctx->ww_ctx);
 }
@@ -287,10 +277,8 @@ EXPORT_SYMBOL(drm_modeset_acquire_fini);
  */
 void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx)
 {
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return;
-#endif
 
 	if (WARN_ON(ctx->contended))
 		__drm_stack_depot_print(ctx->stack_depot);
@@ -312,10 +300,8 @@ static inline int modeset_lock(struct drm_modeset_lock *lock,
 {
 	int ret;
 
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return 0;
-#endif
 
 	if (WARN_ON(ctx->contended))
 		__drm_stack_depot_print(ctx->stack_depot);
@@ -371,10 +357,8 @@ int drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx)
 {
 	struct drm_modeset_lock *contended = ctx->contended;
 
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return 0;
-#endif
 
 	ctx->contended = NULL;
 	ctx->stack_depot = 0;
@@ -420,10 +404,8 @@ EXPORT_SYMBOL(drm_modeset_lock_init);
 int drm_modeset_lock(struct drm_modeset_lock *lock,
 		struct drm_modeset_acquire_ctx *ctx)
 {
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return 0;
-#endif
 
 	if (ctx)
 		return modeset_lock(lock, ctx, ctx->interruptible, false);
@@ -444,10 +426,8 @@ EXPORT_SYMBOL(drm_modeset_lock);
  */
 int drm_modeset_lock_single_interruptible(struct drm_modeset_lock *lock)
 {
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return 0;
-#endif
 	return ww_mutex_lock_interruptible(&lock->mutex, NULL);
 }
 EXPORT_SYMBOL(drm_modeset_lock_single_interruptible);
@@ -458,10 +438,8 @@ EXPORT_SYMBOL(drm_modeset_lock_single_interruptible);
  */
 void drm_modeset_unlock(struct drm_modeset_lock *lock)
 {
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return;
-#endif
 
 	list_del_init(&lock->head);
 	ww_mutex_unlock(&lock->mutex);
@@ -496,10 +474,8 @@ int drm_modeset_lock_all_ctx(struct drm_device *dev,
 	struct drm_plane *plane;
 	int ret;
 
-#ifdef __FreeBSD__
 	if (oops_in_progress)
 		return 0;
-#endif
 
 	ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
 	if (ret)