staging: vchiq_core: simplify WARN_ON conditions

During a recent review Dan Carpenter noticed a double negation in a WARN_ON.
But a quick search revealed more unnecessary complex WARN_ON conditions.
This change should simplify them.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1622735405-9980-11-git-send-email-stefan.wahren@i2se.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>