ion: dummy driver: use ARRAY_SIZE for nr of heaps

use ARRAY_SIZE to count number of heaps in static array

Signed-off-by: Tomas Winkler <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/android/ion/ion_dummy_driver.c

···
 };
 
 struct ion_platform_data dummy_ion_pdata = {
-	.nr = 4,
+	.nr = ARRAY_SIZE(dummy_heaps),
 	.heaps = dummy_heaps,
 };