ARM: OMAP2+: powerdomain: pwrdm_for_each_clkdm iterate only valid clkdms

No need to invoke callback when the clkdm pointer is NULL.
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

arch/arm/mach-omap2/powerdomain.c

@@ -546,7 +546,8 @@ int pwrdm_for_each_clkdm(struct powerdomain *pwrdm,
 		return -EINVAL;
 
 	for (i = 0; i < PWRDM_MAX_CLKDMS && !ret; i++)
-		ret = (*fn)(pwrdm, pwrdm->pwrdm_clkdms[i]);
+		if (pwrdm->pwrdm_clkdms[i])
+			ret = (*fn)(pwrdm, pwrdm->pwrdm_clkdms[i]);
 
 	return ret;
 }