arch/powerpc/cpu/mpc5xxx/i2c.c: fix GC 4.6 build warnings

Fix:
i2c.c: In function 'wait_for_bb':
i2c.c:104:16: warning: variable 'temp' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Heiko Schocher <hs@denx.de>

arch/powerpc/cpu/mpc5xxx/i2c.c

@@ -100,14 +100,11 @@ static int wait_for_bb(void)
 	status = mpc_reg_in(&regs->msr);
 
 	while (timeout-- && (status & I2C_BB)) {
-#if 1
-		volatile int temp;
 		mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
-		temp = mpc_reg_in(&regs->mdr);
+		(void)mpc_reg_in(&regs->mdr);
 		mpc_reg_out(&regs->mcr, 0, I2C_STA);
 		mpc_reg_out(&regs->mcr, 0, 0);
 		mpc_reg_out(&regs->mcr, I2C_EN, 0);
-#endif
 		udelay(15);
 		status = mpc_reg_in(&regs->msr);
 	}