btrfs-progs: rename raid6.c to raid56.c

This allows us to put raid5 codes into that file other than creating a
new raid5.c.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Makefile.in

@@ -91,7 +91,7 @@ CHECKER_FLAGS := -include $(check_defs) -D__CHECKER__ \
 objects = ctree.o disk-io.o kernel-lib/radix-tree.o extent-tree.o print-tree.o \
 	  root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \
 	  extent-cache.o extent_io.o volumes.o utils.o repair.o \
-	  qgroup.o raid6.o free-space-cache.o kernel-lib/list_sort.o props.o \
+	  qgroup.o raid56.o free-space-cache.o kernel-lib/list_sort.o props.o \
 	  ulist.o qgroup-verify.o backref.o string-table.o task-utils.o \
 	  inode.o file.o find-root.o free-space-tree.o help.o
 cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \

disk-io.h

@@ -190,7 +190,7 @@ int write_tree_block(struct btrfs_trans_handle *trans,
 int write_and_map_eb(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		     struct extent_buffer *eb);
 
-/* raid6.c */
+/* raid56.c */
 void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs);
 
 #endif