zms: add more robustiness in extreme cases

When power cuts during a GC operation, the sector is erased again in the
next reboot cycle and the cycle_cnt of the empty ATE is incremented.
If the same power cut happens 255 times in a row, the empty ATE cycle_cnt
will become equal to the close ATE which causes a memory corruption.
Fix this by checking the close ATE cycle_cnt before incrementing the
empty ATE cycle_cnt.

Fixes: #84874
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>