top: fix an improper behavior following a SIGWINCH bug

top: fix an improper behavior following a SIGWINCH bug

When top was made more responsive to keyboard input in
that commit referenced below, his previous response to
a SIGWINCH was upset. Formerly, that display integrity
was restored with the next refresh cycle. But, without
this patch, one must strike some key to accomplish it.

[ in truth, this patch vastly improves that sigwinch ]
[ response. whereas before, although integrity would ]
[ be restored automatically, it did not happen until ]
[ the next regular refresh. now it is instantaneous! ]

Reference(s):
. May, 2022 - made more responsive to kdb input
commit 3ea1bc779fb7ca5bf065a5ca620ec5b5823bc61c

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