EDAC: Use kcalloc()

It is syntactic sugar anyway:

  # drivers/edac/edac_mc.o:

   text    data     bss     dec     hex filename
  13378     324       8   13710    358e edac_mc.o.before
  13378     324       8   13710    358e edac_mc.o.after

md5:
   70a53ee3ac7f867730e35c2be9110748  edac_mc.o.before.asm
   70a53ee3ac7f867730e35c2be9110748  edac_mc.o.after.asm

  # drivers/edac/edac_device.o:

   text    data     bss     dec     hex filename
   5704     120       4    5828    16c4 edac_device.o.before
   5704     120       4    5828    16c4 edac_device.o.after

md5:
   880563c859da6eb9aca85ec431fdbaeb  edac_device.o.before.asm
   880563c859da6eb9aca85ec431fdbaeb  edac_device.o.after.asm

No functional changes.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220412211957.28899-1-bp@alien8.de