net: thunderx: Fix issue with IRQ namimg

This patch fixes a regression caused by previous commit
when irq name exceeds 20 byte array if interface's name
size is large.

Fixes: e4126213 ("net: thunderx: Use netdev's name for naming VF's interrupts")
Signed-off-by: NSunil Goutham <sgoutham@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/thunder/nic.h

@@ -305,7 +305,7 @@ struct nicvf {
 	bool			msix_enabled;
 	u8			num_vec;
 	struct msix_entry	msix_entries[NIC_VF_MSIX_VECTORS];
-	char			irq_name[NIC_VF_MSIX_VECTORS][20];
+	char			irq_name[NIC_VF_MSIX_VECTORS][IFNAMSIZ + 15];
 	bool			irq_allocated[NIC_VF_MSIX_VECTORS];
 	cpumask_var_t		affinity_mask[NIC_VF_MSIX_VECTORS];