memstick/ms_block: Fix some incorrect memory allocation

memstick/ms_block: Fix some incorrect memory allocation

[ Upstream commit aa15913163e91df46425c4a818a6df546edce6fb ]

Some functions of the bitmap API take advantage of the fact that a bitmap
is an array of long.

So, to make sure this assertion is correct, allocate bitmaps with
bitmap_zalloc() instead of kzalloc()+hand-computed number of bytes.

While at it, also use bitmap_free() instead of kfree() to keep the
semantic.

Fixes: f5fd04826d7e ("memstick: add support for legacy memorysticks")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/dbf633c48c24ae6d95f852557e8d8b3bbdef65fe.1656155715.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>