sxgbe: Fix off by one in samsung driver strncpy size arg

This patch fixes an off-by-one error in strncpy size argument in
drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c. The issue is that in:

        strncmp(opt, "eee_timer:", 6)

the passed string literal: "eee_timer:" has 10 bytes (without the NULL
byte) and the passed size argument is 6. As a result, the logic will
also accept other, malformed strings, e.g. "eee_tiXXX:".

This bug doesn't seem to have any security impact since its present in
module's cmdline parsing code.
Signed-off-by: Dominik Czarnota <dominik.b.czarnota@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c

@@ -2277,7 +2277,7 @@ static int __init sxgbe_cmdline_opt(char *str)
 	if (!str || !*str)
 		return -EINVAL;
 	while ((opt = strsep(&str, ",")) != NULL) {
-		if (!strncmp(opt, "eee_timer:", 6)) {
+		if (!strncmp(opt, "eee_timer:", 10)) {
 			if (kstrtoint(opt + 10, 0, &eee_timer))
 				goto err;
 		}