EDAC/pci: Get rid of the silly one-shot memory allocation in edac_pci_alloc_ctl_info()

Use boring kzalloc() instead.

There should be no functional changes resulting from this.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220310095254.1510-3-bp@alien8.de