selftests/damon: fix selftests by installing drgn related script

drgn_dump_damon_status is not installed during kselftest setup. It can
break other tests which depend on drgn_dump_damon_status. Install
drgn_dump_damon_status files to fix broken test.

Link: https://lkml.kernel.org/r/[e-mail]
Fixes: f3e8e1e51362 ("selftests/damon: add drgn script for extracting damon status")
Signed-off-by: Sang-Heon Jeon <[e-mail]>
Reviewed-by: SeongJae Park <[e-mail]>
Cc: Alexandre Ghiti <[e-mail]>
Cc: Honggyu Kim <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

tools/testing/selftests/damon/Makefile

···
 TEST_GEN_FILES += access_memory access_memory_even
 
 TEST_FILES = _damon_sysfs.py
+TEST_FILES += drgn_dump_damon_status.py
 
 # functionality tests
 TEST_PROGS += sysfs.sh