m68k: net: Fix unused variable in mcfmii.c

The following warning was produced, fix it:

mcfmii.c: In function 'mcffec_miiphy_write':
mcfmii.c:318:8: warning: variable 'rdreg' set but not used [-Wunused-but-set-variable]

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: "Jin Zhengxiong-R64188" <R64188@freescale.com>
Cc: Jason Jin <jason.jin@freescale.com>

drivers/net/mcfmii.c

@@ -315,13 +315,11 @@ int mcffec_miiphy_read(const char *devname, unsigned char addr, unsigned char re
 int mcffec_miiphy_write(const char *devname, unsigned char addr, unsigned char reg,
 			unsigned short value)
 {
-	short rdreg;		/* register working value */
-
 #ifdef MII_DEBUG
 	printf("miiphy_write(0x%x) @ 0x%x = ", reg, addr);
 #endif
 
-	rdreg = mii_send(mk_mii_write(addr, reg, value));
+	mii_send(mk_mii_write(addr, reg, value));
 
 #ifdef MII_DEBUG
 	printf("0x%04x\n", value);