On undefined checks, use STDOUT only for the not found entries.

All other data (search-string and show-hints) is printed at
STDERR.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/51c6a39c82f73b441030c51bf905a1f382452a67.1632823172.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>