proc: make struct proc_dir_entry::namelen unsigned int

proc: make struct proc_dir_entry::namelen unsigned int

1. namelen is declared "unsigned short" which hints for "maybe space savings".
   Indeed in 2.4 struct proc_dir_entry looked like:

        struct proc_dir_entry {
                unsigned short low_ino;
                unsigned short namelen;

   Now, low_ino is "unsigned int", all savings were gone for a long time.
   "struct proc_dir_entry" is not that countless to worry about it's size,
   anyway.

2. converting from unsigned short to int/unsigned int can only create
   problems, we better play it safe.

Space is not really conserved, because of natural alignment for the next
field.  sizeof(struct proc_dir_entry) remains the same.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>