mm/damon/vaddr-test: remove unnecessary variables

A couple of test functions in DAMON virtual address space monitoring
primitives implementation has unnecessary damon_ctx variables.  This
commit removes those.

Link: https://lkml.kernel.org/r/20211201150440.1088-7-sj@kernel.org


Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>