refactored printing of the kernel warning:

"orion_mpp_conf: requested MPP%u config unavailable on this hardware\n"

which is not to be printed in case of variant_mask = 0 (unknown variant).
This check should be performed using a logical AND (&&) as opposed
to a bitwise AND (&).

Otherwise, test would fail (and message would not be printed) if
variant_mask != 1
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Olof Johansson <olof@lixom.net>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Holger Brunck <holger.brunck@keymile.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>