[PATCH] missing null termination in power supply uevent

Need to null terminate environment. Found by inspection
while looking for similar problems to platform uevent bug

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
index c7c4574..de3155b 100644
--- a/drivers/power/power_supply_sysfs.c
+++ b/drivers/power/power_supply_sysfs.c
@@ -289,6 +289,7 @@
 		if (ret)
 			goto out;
 	}
+	envp[i] = NULL;
 
 out:
 	free_page((unsigned long)prop_buf);