net: use netif_is_bridge_port() to check for IFF_BRIDGE_PORT

net: use netif_is_bridge_port() to check for IFF_BRIDGE_PORT

BugLink: https://bugs.launchpad.net/bugs/1951883
[ Upstream commit 2e92a2d0e450740ebe7e7a816162327ad1fde94b ]

Trivial cleanup, so that all bridge port-specific code can be found in
one go.

CC: Johannes Berg <johannes@sipsolutions.net>
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>