i5000: Fix the memory size calculation with 2R memories

When 2R memories are found, the memory size should be multiplied
by two, otherwise, it will report half of the memory size:

       +-----------------------------------------------+
       |                      mc0                      |
       |        branch0        |        branch1        |
       | channel0  | channel1  | channel0  | channel1  |
-------+-----------------------------------------------+
slot3: |     0 MB  |     0 MB  |     0 MB  |     0 MB  |
slot2: |     0 MB  |     0 MB  |     0 MB  |     0 MB  |
-------+-----------------------------------------------+
slot1: |     0 MB  |     0 MB  |     0 MB  |     0 MB  |
slot0: |  1024 MB  |  1024 MB  |  1024 MB  |  1024 MB  |
-------+-----------------------------------------------+

(the above machine have 4 x 2GB 2R memories)

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/edac/i5000_edac.c b/drivers/edac/i5000_edac.c
index 39c6375..6a49dd0 100644
--- a/drivers/edac/i5000_edac.c
+++ b/drivers/edac/i5000_edac.c
@@ -1012,6 +1012,10 @@
 			/* add the number of COLUMN bits */
 			addrBits += MTR_DIMM_COLS_ADDR_BITS(mtr);
 
+			/* Dual-rank memories have twice the size */
+			if (dinfo->dual_rank)
+				addrBits++;
+
 			addrBits += 6;	/* add 64 bits per DIMM */
 			addrBits -= 20;	/* divide by 2^^20 */
 			addrBits -= 3;	/* 8 bits per bytes */