scripts/nsdeps: adjust to the format change of *.mod files

Commit 22f26f21 ("kbuild: get rid of duplication in *.mod files")
changed the format of *.mod files to put one object per line, but missed
to adjust scripts/nsdeps.

Fixes: 22f26f21

 ("kbuild: get rid of duplication in *.mod files")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>