top: traded just one 'goto' for a more appropriate one

This was an oops resulting from the refactored help in
the commit referenced below. Should a '-1' be returned
from iokey(), we would display the windows help screen
instead of remaining on this primary/main help screen.

[ '-1' only happens when a user types an escaped key ]
[ combo that can't be translated into a known value. ]
[ for example, keying something like a 'Ctrl+Alt+A'. ]

Reference(s):
. Aug, 2025 - help refactored
commit 3dc54f52

Signed-off-by: Jim Warner <james.warner@comcast.net>