selftests/mm: include strings.h for ffsl

Got a compilation error on Android for ffsl after 91b80cc5b39f
("selftests: mm: fix map_hugetlb failure on 64K page size systems")
included vm_util.h.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: af605d26a8f2 ("selftests/mm: merge util.h into vm_util.h")
Signed-off-by: Edward Liaw <[email protected]>
Reviewed-by: Muhammad Usama Anjum <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Mike Rapoport (IBM)" <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions