net: mscc: ocelot: Fix some struct initializations

Clang warns:

drivers/net/ethernet/mscc/ocelot_ace.c:335:37: warning: suggest braces
around initialization of subobject [-Wmissing-braces]
        struct ocelot_vcap_u64 payload = { 0 };
                                           ^
                                           {}
drivers/net/ethernet/mscc/ocelot_ace.c:336:28: warning: suggest braces
around initialization of subobject [-Wmissing-braces]
        struct vcap_data data = { 0 };
                                  ^
                                  {}
drivers/net/ethernet/mscc/ocelot_ace.c:683:37: warning: suggest braces
around initialization of subobject [-Wmissing-braces]
        struct ocelot_ace_rule del_ace = { 0 };
                                           ^
                                           {}
drivers/net/ethernet/mscc/ocelot_ace.c:743:28: warning: suggest braces
around initialization of subobject [-Wmissing-braces]
        struct vcap_data data = { 0 };
                                  ^
                                  {}
4 warnings generated.

One way to fix these warnings is to add additional braces like Clang
suggests; however, there has been a bit of push back from some
maintainers[1][2], who just prefer memset as it is unambiguous, doesn't
depend on a particular compiler version[3], and properly initializes all
subobjects. Do that here so there are no more warnings.

[1]: https://lore.kernel.org/lkml/022e41c0-8465-dc7a-a45c-64187ecd9684@amd.com/
[2]: https://lore.kernel.org/lkml/20181128.215241.702406654469517539.davem@davemloft.net/
[3]: https://lore.kernel.org/lkml/20181116150432.2408a075@redhat.com/

Fixes: b596229 ("net: mscc: ocelot: Add support for tcam")
Link: https://github.com/ClangBuiltLinux/linux/issues/505
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot_ace.c

@@ -332,10 +332,13 @@ static void is2_entry_set(struct ocelot *ocelot, int ix,
 {
 	u32 val, msk, type, type_mask = 0xf, i, count;
 	struct ocelot_ace_vlan *tag = &ace->vlan;
-	struct ocelot_vcap_u64 payload = { 0 };
-	struct vcap_data data = { 0 };
+	struct ocelot_vcap_u64 payload;
+	struct vcap_data data;
 	int row = (ix / 2);
 
+	memset(&payload, 0, sizeof(payload));
+	memset(&data, 0, sizeof(data));
+
 	/* Read row */
 	vcap_row_cmd(ocelot, row, VCAP_CMD_READ, VCAP_SEL_ALL);
 	vcap_cache2entry(ocelot, &data);
@@ -680,10 +683,12 @@ static void ocelot_ace_rule_del(struct ocelot_acl_block *block,
 
 int ocelot_ace_rule_offload_del(struct ocelot_ace_rule *rule)
 {
-	struct ocelot_ace_rule del_ace = { 0 };
+	struct ocelot_ace_rule del_ace;
 	struct ocelot_ace_rule *ace;
 	int i, index;
 
+	memset(&del_ace, 0, sizeof(del_ace));
+
 	/* Gets index of the rule */
 	index = ocelot_ace_rule_get_index_id(acl_block, rule);
 
@@ -740,8 +745,9 @@ static void ocelot_acl_block_destroy(struct ocelot_acl_block *block)
 
 int ocelot_ace_init(struct ocelot *ocelot)
 {
-	struct vcap_data data = { 0 };
+	struct vcap_data data;
 
+	memset(&data, 0, sizeof(data));
 	vcap_entry2cache(ocelot, &data);
 	ocelot_write(ocelot, vcap_is2.entry_count, S2_CORE_MV_CFG);
 	vcap_cmd(ocelot, 0, VCAP_CMD_INITIALIZE, VCAP_SEL_ENTRY);