net: bridge: use sysfs_emit instead of sprintf

net: bridge: use sysfs_emit instead of sprintf

Replace sprintf with sysfs_emit in sysfs show() methods as outlined in
Documentation/filesystems/sysfs.rst.

sysfs_emit is preferred to sprintf in sysfs show() methods as it is safer
with buffer handling.

Signed-off-by: David Corvaglia <david@corvaglia.dev>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/0100019c1fc2bcc3-bc9ca2f1-22d7-4250-8441-91e4af57117b-000000@email.amazonses.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>