EDAC/device: Remove edac_dev_sysfs_block_attribute::store()

EDAC/device: Remove edac_dev_sysfs_block_attribute::store()

No one uses this store hook (both BLOCK_ATTR() pass NULL). It actually
never was since its addition in

  fd309a9d8e63 ("drivers/edac: fix leaf sysfs attribute")

so drop it.

Found by https://github.com/jirislaby/clang-struct.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240213112051.27715-4-jirislaby@kernel.org
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>