sb_edac: Fix typo computing number of banks

Code will always think there are 16 banks because of a typo

Reported-by: Misha
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/edac/sb_edac.c

@@ -901,7 +901,7 @@ static int get_dimm_config(struct mem_ctl_info *mci)
 	else
 		edac_dbg(0, "Memory is unregistered\n");
 
-	if (mtype == MEM_DDR4 || MEM_RDDR4)
+	if (mtype == MEM_DDR4 || mtype == MEM_RDDR4)
 		banks = 16;
 	else
 		banks = 8;