Fix the error handling of some LED _store functions.  This corrects them to
return -EINVAL if the value is not numeric with an optional byte of trailing
whitespace.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>