EDAC, MCE: Overhaul error fields extraction macros

Make macro names shorter thus making code shorter and more clear.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index eca9ba1..0212232 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -2055,8 +2055,8 @@
 static inline void __amd64_decode_bus_error(struct mem_ctl_info *mci,
 					    struct err_regs *info)
 {
-	u32 ec  = ERROR_CODE(info->nbsl);
-	u32 xec = EXT_ERROR_CODE(info->nbsl);
+	u16 ec = EC(info->nbsl);
+	u8 xec = XEC(info->nbsl, 0x1f);
 	int ecc_type = (info->nbsh >> 13) & 0x3;
 
 	/* Bail early out if this was an 'observed' error */