btrfs: drop null testing before destroy functions

Cleanup.

kmem_cache_destroy has support NULL argument checking,
so drop the double null testing before calling it.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/backref.c

@@ -148,7 +148,6 @@ int __init btrfs_prelim_ref_init(void)
 
 void btrfs_prelim_ref_exit(void)
 {
-	if (btrfs_prelim_ref_cache)
 	kmem_cache_destroy(btrfs_prelim_ref_cache);
 }
 

fs/btrfs/delayed-inode.c

@@ -43,7 +43,6 @@ int __init btrfs_delayed_inode_init(void)
 
 void btrfs_delayed_inode_exit(void)
 {
-	if (delayed_node_cache)
 	kmem_cache_destroy(delayed_node_cache);
 }
 

fs/btrfs/delayed-ref.c

@@ -929,13 +929,9 @@ btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
 
 void btrfs_delayed_ref_exit(void)
 {
-	if (btrfs_delayed_ref_head_cachep)
 	kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
-	if (btrfs_delayed_tree_ref_cachep)
 	kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
-	if (btrfs_delayed_data_ref_cachep)
 	kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
-	if (btrfs_delayed_extent_op_cachep)
 	kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
 }
 

fs/btrfs/disk-io.c

@@ -110,7 +110,6 @@ int __init btrfs_end_io_wq_init(void)
 
 void btrfs_end_io_wq_exit(void)
 {
-	if (btrfs_end_io_wq_cache)
 	kmem_cache_destroy(btrfs_end_io_wq_cache);
 }
 

fs/btrfs/extent_io.c

@@ -206,9 +206,7 @@ void extent_io_exit(void)
 	 * destroy caches.
 	 */
 	rcu_barrier();
-	if (extent_state_cache)
 	kmem_cache_destroy(extent_state_cache);
-	if (extent_buffer_cache)
 	kmem_cache_destroy(extent_buffer_cache);
 	if (btrfs_bioset)
 		bioset_free(btrfs_bioset);

fs/btrfs/extent_map.c

@@ -20,7 +20,6 @@ int __init extent_map_init(void)
 
 void extent_map_exit(void)
 {
-	if (extent_map_cache)
 	kmem_cache_destroy(extent_map_cache);
 }
 

fs/btrfs/file.c

@@ -2939,7 +2939,6 @@ const struct file_operations btrfs_file_operations = {
 
 void btrfs_auto_defrag_exit(void)
 {
-	if (btrfs_inode_defrag_cachep)
 	kmem_cache_destroy(btrfs_inode_defrag_cachep);
 }
 

fs/btrfs/inode.c

@@ -9178,15 +9178,10 @@ void btrfs_destroy_cachep(void)
 	 * destroy cache.
 	 */
 	rcu_barrier();
-	if (btrfs_inode_cachep)
 	kmem_cache_destroy(btrfs_inode_cachep);
-	if (btrfs_trans_handle_cachep)
 	kmem_cache_destroy(btrfs_trans_handle_cachep);
-	if (btrfs_transaction_cachep)
 	kmem_cache_destroy(btrfs_transaction_cachep);
-	if (btrfs_path_cachep)
 	kmem_cache_destroy(btrfs_path_cachep);
-	if (btrfs_free_space_cachep)
 	kmem_cache_destroy(btrfs_free_space_cachep);
 }
 

fs/btrfs/ordered-data.c

@@ -1114,6 +1114,5 @@ int __init ordered_data_init(void)
 
 void ordered_data_exit(void)
 {
-	if (btrfs_ordered_extent_cache)
 	kmem_cache_destroy(btrfs_ordered_extent_cache);
 }