insert_into_cell inserts into wrong free space

[pereman2]

---- storage::btree::tests::test_fuzz_drop_defragment_insert stdout ----
thread 'storage::btree::tests::test_fuzz_drop_defragment_insert' panicked at core/storage/btree.rs:2454:8:
range end index 31488 out of range for slice of length 4096

[krishvishal]

@pereman2 is this failure on current main? I'm unable to reproduce this failure on my machine, I've ran cargo test for 10 times.

[pereman2]

@krishvishal you should probably run it indefinitely until it fails, 10 times might not be significant number.

[krishvishal]

SEED = 15579468246411287112
ERROR = thread 'storage::btree::tests::test_fuzz_drop_defragment_insert' panicked at core/storage/btree.rs:2454:8:
range end index 48128 out of range for slice of length 4096

----------------------------------------------------------

SEED = 8627205560001768239
ERROR = thread 'storage::btree::tests::test_fuzz_drop_defragment_insert' panicked at core/storage/btree.rs:3641:13:
assertion `left == right` failed
  left: 3892
 right: 3896

Found two seeds resulting in different types of error behavior.