util_macros.h: have array pointer point to array of constants

Using the new find_closest() macro can result in the following sparse
warnings.

  drivers/hwmon/lm85.c:194:16: warning:
  		incorrect type in initializer (different modifiers)
  drivers/hwmon/lm85.c:194:16:    expected int *__fc_a
  drivers/hwmon/lm85.c:194:16:    got int static const [toplevel] *<noident>
  drivers/hwmon/lm85.c:210:16: warning:
  		incorrect type in initializer (different modifiers)
  drivers/hwmon/lm85.c:210:16:    expected int *__fc_a
  drivers/hwmon/lm85.c:210:16:    got int const *map

This is because the array passed to find_closest() will typically be
declared as array of constants, but the macro declares a non-constant
pointer to it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>