liquidio: fix Coverity scan errors

Fix Coverity scan errors by not dereferencing lio->glists_dma_base pointer
if it's NULL.

See http://marc.info/?l=linux-netdev&m=149002294305614&w=2

Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: VSR Burru <veerasenareddy.burru@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/liquidio/lio_main.c

@@ -712,7 +712,8 @@ static void delete_glists(struct lio *lio)
 				kfree(g);
 		} while (g);
 
-		if (lio->glists_virt_base && lio->glists_virt_base[i]) {
+		if (lio->glists_virt_base && lio->glists_virt_base[i] &&
+		    lio->glists_dma_base && lio->glists_dma_base[i]) {
 			lio_dma_free(lio->oct_dev,
 				     lio->glist_entry_size * lio->tx_qsize,
 				     lio->glists_virt_base[i],

drivers/net/ethernet/cavium/liquidio/lio_vf_main.c

@@ -470,7 +470,8 @@ static void delete_glists(struct lio *lio)
 				kfree(g);
 		} while (g);
 
-		if (lio->glists_virt_base && lio->glists_virt_base[i]) {
+		if (lio->glists_virt_base && lio->glists_virt_base[i] &&
+		    lio->glists_dma_base && lio->glists_dma_base[i]) {
 			lio_dma_free(lio->oct_dev,
 				     lio->glist_entry_size * lio->tx_qsize,
 				     lio->glists_virt_base[i],