lib/debug: Convert igt_drop_caches_set() to use common file writers

Why open code a printf/write loop, when we already have a function
providing it?

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com
1 file changed