sh: sq: Fix incorrect element size for allocating bitmap buffer

The Store Queue code allocates a bitmap buffer with the size of
multiple of sizeof(long) in sq_api_init(). While the buffer size
is calculated correctly, the code uses the wrong element size to
allocate the buffer which results in the allocated bitmap buffer
being too small.

Fix this by allocating the buffer with kcalloc() with element size
sizeof(long) instead of kzalloc() whose elements size defaults to
sizeof(char).

Fixes: d7c30c68 ("sh: Store Queue API rework.")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20230419114854.528677-1-glaubitz@physik.fu-berlin.de