staging: panel: pass correct lengths to keypad_send_key()

We changed the sizeof() statements in 429ccf05 "staging:panel: Fixed
coding conventions." so that they could fit inside the 80 character
line limit.  Unfortunately, the new sizeof() statements are a smaller
size.  This reverts it.

There isn't a nice way to stay within the 80 character limit without
a re-work so I've gone over.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>