NetLabel: only deref the CIPSOv4 standard map fields when using standard mapping

Fix several places in the CIPSO code where it was dereferencing fields which
did not have valid pointers by moving those pointer dereferences into code
blocks where the pointers are valid.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index bde8cca..d19c9ac 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -773,13 +773,15 @@
 {
 	int cat = -1;
 	u32 bitmap_len_bits = bitmap_len * 8;
-	u32 cipso_cat_size = doi_def->map.std->cat.cipso_size;
-	u32 *cipso_array = doi_def->map.std->cat.cipso;
+	u32 cipso_cat_size;
+	u32 *cipso_array;
 
 	switch (doi_def->type) {
 	case CIPSO_V4_MAP_PASS:
 		return 0;
 	case CIPSO_V4_MAP_STD:
+		cipso_cat_size = doi_def->map.std->cat.cipso_size;
+		cipso_array = doi_def->map.std->cat.cipso;
 		for (;;) {
 			cat = cipso_v4_bitmap_walk(bitmap,
 						   bitmap_len_bits,
@@ -825,8 +827,8 @@
 	u32 net_spot_max = 0;
 	u32 host_clen_bits = host_cat_len * 8;
 	u32 net_clen_bits = net_cat_len * 8;
-	u32 host_cat_size = doi_def->map.std->cat.local_size;
-	u32 *host_cat_array = doi_def->map.std->cat.local;
+	u32 host_cat_size;
+	u32 *host_cat_array;
 
 	switch (doi_def->type) {
 	case CIPSO_V4_MAP_PASS:
@@ -838,6 +840,8 @@
 		memcpy(net_cat, host_cat, net_spot_max);
 		return net_spot_max;
 	case CIPSO_V4_MAP_STD:
+		host_cat_size = doi_def->map.std->cat.local_size;
+		host_cat_array = doi_def->map.std->cat.local;
 		for (;;) {
 			host_spot = cipso_v4_bitmap_walk(host_cat,
 							 host_clen_bits,
@@ -893,8 +897,8 @@
 	int net_spot = -1;
 	u32 net_clen_bits = net_cat_len * 8;
 	u32 host_clen_bits = host_cat_len * 8;
-	u32 net_cat_size = doi_def->map.std->cat.cipso_size;
-	u32 *net_cat_array = doi_def->map.std->cat.cipso;
+	u32 net_cat_size;
+	u32 *net_cat_array;
 
 	switch (doi_def->type) {
 	case CIPSO_V4_MAP_PASS:
@@ -903,6 +907,8 @@
 		memcpy(host_cat, net_cat, net_cat_len);
 		return net_cat_len;
 	case CIPSO_V4_MAP_STD:
+		net_cat_size = doi_def->map.std->cat.cipso_size;
+		net_cat_array = doi_def->map.std->cat.cipso;
 		for (;;) {
 			net_spot = cipso_v4_bitmap_walk(net_cat,
 							net_clen_bits,