Documentation: Use "while" instead of "whilst"

Whilst making an unrelated change to some Documentation, Linus sayeth:

  | Afaik, even in Britain, "whilst" is unusual and considered more
  | formal, and "while" is the common word.
  |
  | [...]
  |
  | Can we just admit that we work with computers, and we don't need to
  | use þe eald Englisc spelling of words that most of the world never
  | uses?

dictionary.com refers to the word as "Chiefly British", which is
probably an undesirable attribute for technical documentation.

Replace all occurrences under Documentation/ with "while".

Cc: David Howells <dhowells@redhat.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michael Halcrow <mhalcrow@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/filesystems/vfs.txt

@@ -1131,7 +1131,7 @@ struct dentry_operations {
 
   d_manage: called to allow the filesystem to manage the transition from a
 	dentry (optional).  This allows autofs, for example, to hold up clients
-	waiting to explore behind a 'mountpoint' whilst letting the daemon go
+	waiting to explore behind a 'mountpoint' while letting the daemon go
 	past and construct the subtree there.  0 should be returned to let the
 	calling process continue.  -EISDIR can be returned to tell pathwalk to
 	use this directory as an ordinary directory and to ignore anything