media: ov9650: remove unnecessary terminated entry in menu items array

The test_pattern_menu[] array has two valid items and a null terminated
item.  So the control's maximum value which is passed to
v4l2_ctrl_new_std_menu_items() should be one.  However,
'ARRAY_SIZE(test_pattern_menu) - 1' is actually passed and it's not
correct.

Fix it by removing unnecessary terminated entry and let the correct
control's maximum value be passed to v4l2_ctrl_new_std_menu_items().

Cc: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>