ARM: ux500: Rid ignored return value of regulator_enable() compiler warning

arch/arm/mach-ux500/board-mop500.c: In function ‘mop500_prox_activate’:
arch/arm/mach-ux500/board-mop500.c:406:18: warning: ignoring return value of
        ‘regulator_enable’, declared with attribute warn_unused_result
        [-Wunused-result]
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

arch/arm/mach-ux500/board-mop500.c

@@ -403,8 +403,8 @@ static int mop500_prox_activate(struct device *dev)
 			"no regulator\n");
 		return PTR_ERR(prox_regulator);
 	}
-	regulator_enable(prox_regulator);
-	return 0;
+
+	return regulator_enable(prox_regulator);
 }
 
 static void mop500_prox_deactivate(struct device *dev)