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>
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index faebd5f..f391948 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -546,7 +546,8 @@
 		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;
 }