hfsplus: rework logic of map nodes creation in xattr b-tree

hfsplus: rework logic of map nodes creation in xattr b-tree

In hfsplus_init_header_node() when node_count > 63488
(header bitmap capacity), the code calculates map_nodes,
subtracts them from free_nodes, and marks their positions
used in the bitmap. However, it doesn't write the actual
map node structure (type, record offsets, bitmap) for
those physical positions, only node 0 is written.

This patch reworks hfsplus_create_attributes_file()
logic by introducing a specialized method of
hfsplus_init_map_node() and writing the allocated
map b-tree's nodes by means of
hfsplus_write_attributes_file_node() method.

cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Link: https://lore.kernel.org/r/20260403230556.614171-5-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>