net: phy: Fix truncation of large IRQ numbers in phy_attached_print()

Given NR_IRQS is 2048 on sparc64, and even 32784 on alpha, 3 digits is
not enough to represent interrupt numbers on all architectures.  Hence
PHY interrupt numbers may be truncated during printing.

Increase the buffer size from 4 to 8 bytes to fix this.

Fixes: 5e369aef ("net: stmmac: Delete dead code for MDIO registration")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -879,7 +879,7 @@ void phy_attached_print(struct phy_device *phydev, const char *fmt, ...)
 {
 	const char *drv_name = phydev->drv ? phydev->drv->name : "unbound";
 	char *irq_str;
-	char irq_num[4];
+	char irq_num[8];
 
 	switch(phydev->irq) {
 	case PHY_POLL: