net: bgmac: Fix SOF bit checking

net: bgmac: Fix SOF bit checking

commit d2b13233879ca1268a1c027d4573109e5a777811 upstream.

We are checking for the Start of Frame bit in the ctl1 word, while this
bit is set in the ctl0 word instead. Read the ctl0 word and update the
check to verify that.

Fixes: 9cde94506eac ("bgmac: implement scatter/gather support")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>