net: qca_spi: Fix log level if probe fails

[ Upstream commit 50973993 ]

In cases the probing fails the log level of the messages should
be an error.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>