The console message text for gpio hog errors does not match
what unittest expects.

Fixes: f4056e70 ("of: unittest: add overlay gpio test to catch gpio hog problem")
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Link: https://lore.kernel.org/r/20211029013225.2048695-1-frowand.list@gmail.comSigned-off-by: Rob Herring <robh@kernel.org>