memstick/ms_block: Fix a memory leak

memstick/ms_block: Fix a memory leak

'erased_blocks_bitmap' is never freed. As it is allocated at the same time
as 'used_blocks_bitmap', it is likely that it should be freed also at the
same time.

Add the corresponding bitmap_free() in msb_data_clear().

Fixes: 0ab30494bc4f ("memstick: add support for legacy memorysticks")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/b3b78926569445962ea5c3b6e9102418a9effb88.1656155715.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>