RTC: Fix minor compile warning

Two rtc drivers return values from void functions. This patch
fixes that.

CC: Thomas Gleixner <tglx@linutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

drivers/rtc/rtc-msm6242.c

@@ -82,7 +82,7 @@ static inline unsigned int msm6242_read(struct msm6242_priv *priv,
 static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val,
 				unsigned int reg)
 {
-	return __raw_writel(val, &priv->regs[reg]);
+	__raw_writel(val, &priv->regs[reg]);
 }
 
 static inline void msm6242_set(struct msm6242_priv *priv, unsigned int val,

drivers/rtc/rtc-rp5c01.c

@@ -76,7 +76,7 @@ static inline unsigned int rp5c01_read(struct rp5c01_priv *priv,
 static inline void rp5c01_write(struct rp5c01_priv *priv, unsigned int val,
 				unsigned int reg)
 {
-	return __raw_writel(val, &priv->regs[reg]);
+	__raw_writel(val, &priv->regs[reg]);
 }
 
 static void rp5c01_lock(struct rp5c01_priv *priv)