net: mvpp2: debugfs: fix incorrect bitwise operator

The use of the | operator always leads to true, which looks rather
suspect in this case.

Fix this by using & instead.

Addresses-Coverity-ID: 1471903 ("Wrong operator used")
Fixes: dba1d918 ("net: mvpp2: debugfs: add entries for classifier flows")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>