mfd/asic3: fix asic3_mfd_probe return value

In commit 4f304245 "mfd: Set asic3 DS1WM clock_rate", a possible
path through asic3_mfd_probe was introduced that would lead to
an unpredictable return value, if everything succeeds but there
are pdata->leds is NULL. This was reported correctly by gcc.

Without this patch, building magician_defconfig results in:

drivers/mfd/asic3.c: In function 'asic3_mfd_probe':
drivers/mfd/asic3.c:940:2: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Parsons <lost.distance@yahoo.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/asic3.c

@@ -925,6 +925,7 @@ static int __init asic3_mfd_probe(struct platform_device *pdev,
 			goto out;
 	}
 
+	ret = 0;
 	if (pdata->leds) {
 		int i;