proc: Make inline name size calculation automatic

proc: Make inline name size calculation automatic

Make calculation of the size of the inline name in struct proc_dir_entry
automatic, rather than having to manually encode the numbers and failing to
allow for lockdep.

Require a minimum inline name size of 33+1 to allow for names that look
like two hex numbers with a dash between.

Reported-by: Al Viro <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Al Viro <[email protected]>