tg3: Add braces around 5906 workaround.

Commit dabc5c6, entitled
"tg3: Move TSO_CAPABLE assignment", moved some TSO flagging code around.
In the process it failed to add braces around an exceptional 5906
condition.  This patch fixes the problem.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tg3.c

@@ -13707,9 +13707,11 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
 				     tp->pcie_cap + PCI_EXP_LNKCTL,
 				     &lnkctl);
 		if (lnkctl & PCI_EXP_LNKCTL_CLKREQ_EN) {
-			if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5906)
+			if (GET_ASIC_REV(tp->pci_chip_rev_id) ==
+			    ASIC_REV_5906) {
 				tg3_flag_clear(tp, HW_TSO_2);
 				tg3_flag_clear(tp, TSO_CAPABLE);
+			}
 			if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5784 ||
 			    GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5761 ||
 			    tp->pci_chip_rev_id == CHIPREV_ID_57780_A0 ||