Andrey Konovalov reported an issue with proc_register in bcm.c.
As suggested by Cong Wang this patch adds a lock_sock() protection and
a check for unsuccessful proc_create_data() in bcm_connect().

Reference: http://marc.info/?l=linux-netdev&m=147732648731237Reported-by: NAndrey Konovalov <andreyknvl@google.com>
Suggested-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Tested-by: NAndrey Konovalov <andreyknvl@google.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>