We do not have headers at all in this file. We should have them so that
not every .c file needs to include all of the stuff which this file need
for building. This way we can remove some headers from other files and
get better picture what is needed. This can save some compilation time.
And this can help if we sometimes want to separate this one big header.

Also use forward declarations for structs and enums when it not included
straight with include and it is used in function declarations input.
This will prevent possible compiler warning:
  xxx declared inside parameter list will not be visible
  outside of this definition or declaration

Here is list which I made when parsing this. There is not necessarily
all example from this header file, but this just proofs we need it.

<linux/blkdev.h> SECTOR_SHIFT
<linux/buffer_head.h> sb_bread(), put_bh
<linux/cleancache.h> put_page()
<linux/fs.h> struct inode (Just struct ntfs_inode need it)
<linux/highmem.h> kunmap(), kmap()
<linux/kernel.h> cpu_to_leXX() ALIGN
<linux/mm.h> kvfree()
<linux/mutex.h> struct mutex, mutex_(un/try)lock()
<linux/page-flags.h> PageError()
<linux/pagemap.h> read_mapping_page()
<linux/rbtree.h> struct rb_root
<linux/rwsem.h> struct rw_semaphore
<linux/slab.h> krfree(), kzalloc()
<linux/string.h> memset()
<linux/time64.h> struct timespec64
<linux/types.h> uXX, __leXX
<linux/uidgid.h> kuid_t, kgid_t
<asm/div64.h> do_div()
<asm/page.h> PAGE_SIZE

"debug.h" ntfs_err() (Just one entry. Maybe we can drop this)
"ntfs.h" Do you even ask?
Signed-off-by: Kari Argillander <kari.argillander@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>