brcm47xx: bgmac: allow bigger et_swtype nvram variable

Without this patch it is impossible to read et_swtype, because the 1
byte space is needed for the terminating null byte. Now it should be
possible to read decimal and hex vars of max 8 bit.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 37999

target/linux/brcm47xx/patches-3.10/711-bgmac_fix_parsing_of_et_swtype.patch

+--- a/drivers/net/ethernet/broadcom/bgmac.c
++++ b/drivers/net/ethernet/broadcom/bgmac.c
+@@ -909,9 +909,9 @@ static void bgmac_chip_reset(struct bgma
+ 		u8 et_swtype = 0;
+ 		u8 sw_type = BGMAC_CHIPCTL_1_SW_TYPE_EPHY |
+ 			     BGMAC_CHIPCTL_1_IF_TYPE_MII;
+-		char buf[2];
++		char buf[4];
+ 
+-		if (bcm47xx_nvram_getenv("et_swtype", buf, 1) > 0) {
++		if (bcm47xx_nvram_getenv("et_swtype", buf, sizeof(buf)) > 0) {
+ 			if (kstrtou8(buf, 0, &et_swtype))
+ 				bgmac_err(bgmac, "Failed to parse et_swtype (%s)\n",
+ 					  buf);