bonding: fix second off-by-one error

Fix off-by-one error because IFNAMSIZ == 16 and when this
code gets executed we stick a NULL byte where we should not.

How to reproduce:
with CONFIG_CC_STACKPROTECTOR=y (otherwise it may pass by silently)
modprobe bonding; echo 1 > /sys/class/net/bond0/bonding/mode;
echo "AAAAAAAAAAAAAAAA" > /sys/class/net/bond0/bonding/active_slave;

Signed-off-by: Nikolay Aleksandrov <[e-mail]>

Note: Sorry for the second patch but I missed this one while checking
the file. You can squash them into one patch.
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/bonding/bond_sysfs.c

···
 		goto out;
 	}
 
-	sscanf(buf, "%16s", ifname); /* IFNAMSIZ */
+	sscanf(buf, "%15s", ifname); /* IFNAMSIZ */
 
 	/* check to see if we are clearing active */
 	if (!strlen(ifname) || buf[0] == '\n') {