list: test: fix tests for list_cut_position()

Fix test for list_cut_position*() for the missing check of integer "i"
after the second loop.  The variable should be checked for second time to
make sure both lists after the cut operation are formed as expected.

Link: https://lkml.kernel.org/r/20240910043531.71343-1-richard120310@gmail.com


Signed-off-by: I Hsin Cheng <richard120310@gmail.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>