mm/damon/core: copy struct-to-struct instead of field-to-field in damon_new_scheme()

The function for new 'struct damos' creation, 'damon_new_scheme()', copies
each field of the struct one by one, though it could simply copied via
struct to struct.  This commit replaces the unnecessarily verbose
field-to-field copies with struct-to-struct copies to make code simple and
short.

Link: https://lkml.kernel.org/r/20220913174449.50645-4-sj@kernel.org


Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>