power-supply: Return early if "power-supplies" property isn't valid

If power-supply's DT node doesn't have a valid "power-supplies" entry, then
power_supply_check_supplies() should return early instead of trying to allocate
memory for "supplied_from" array.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

diff --cc drivers/power/power_supply_core.c
Simple merge