edac, mce: Fix wrong mask and macro usage

Correct two mishaps which prevented reporting error type (CECC vs UECC)
and extended error description.

Cc: <stable@kernel.org> # 32.x,  33.x
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>