fix: fio_printf shows wrong message about %x
%x should be unsigned int
w
Add: filename information
add filename length and filename after hash
filename length is fixed 4 bytes,

the struct of a file in the romfs
hash: 4 bytes
filename length: 4 bytes
filename: dynamic length
context size: 4 bytes
context: dynamic length
Add: fs_show_t type
this type is used for callback function of romfs_show
Fix: ls_command
fs_show function shows all of files in the romfs
however, this version cannot show the directory
Add: romfs_show
this function will show all of filename in the romfs.
fix get_file_by_hash, the new romfs has a new structre
Add: fs_show
fs_show can will call the callback function of romfs_show
It will show all filenames in the targeted filesystem