[PATCH] genl: fix ‘attr_grp.next_len’ may be used uninitialized

make --no-print-directory all-am
  CC       ell/genl.lo
ell/genl.c: In function ‘parse_cmd_newfamily.part.0’:
ell/genl.c:1728:5: error: ‘attr_grp.next_len’ may be used uninitialized
in this function [-Werror=maybe-uninitialized]
 1728 |  if (!NLA_OK(nla, attr->next_len))
      |     ^
ell/genl.c:268:22: note: ‘attr_grp.next_len’ was declared here
  268 |   struct l_genl_attr attr_grp;
      |                      ^~~~~~~~
ell/genl.c:1732:14: error: ‘attr_grp.next_data’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]
 1732 |   *type = nla->nla_type & NLA_TYPE_MASK;
      |           ~~~^~~~~~~~~~
ell/genl.c:268:22: note: ‘attr_grp.next_data’ was declared here
  268 |   struct l_genl_attr attr_grp;
      |                      ^~~~~~~~
ell/genl.c:1728:5: error: ‘attr_op.next_len’ may be used uninitialized
in this function [-Werror=maybe-uninitialized]
 1728 |  if (!NLA_OK(nla, attr->next_len))
      |     ^
ell/genl.c:240:22: note: ‘attr_op.next_len’ was declared here
  240 |   struct l_genl_attr attr_op;
      |                      ^~~~~~~
ell/genl.c:1732:14: error: ‘attr_op.next_data’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]
 1732 |   *type = nla->nla_type & NLA_TYPE_MASK;
      |           ~~~^~~~~~~~~~
ell/genl.c:240:22: note: ‘attr_op.next_data’ was declared here
  240 |   struct l_genl_attr attr_op;
      |                      ^~~~~~~
cc1: all warnings being treated as errors
make[1]: *** [Makefile:4032: ell/genl.lo] Error 1
make: *** [Makefile:2348: all] Error 2
---
 ell/genl.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/ell/genl.c b/ell/genl.c
index def3790..33ecc4d 100644
--- a/ell/genl.c
+++ b/ell/genl.c
@@ -240,7 +240,8 @@ static void family_ops(struct l_genl_family_info
*info,
 		struct l_genl_attr attr_op;
 		uint32_t id = 0, flags = 0;
 
-		l_genl_attr_recurse(attr, &attr_op);
+		if (!l_genl_attr_recurse(attr, &attr_op))
+			continue;
 
 		while (l_genl_attr_next(&attr_op, &type, &len, &data))
{
 			switch (type) {
@@ -269,7 +270,8 @@ static void family_mcast_groups(struct
l_genl_family_info *info,
 		const char *name = NULL;
 		uint32_t id = 0;
 
-		l_genl_attr_recurse(attr, &attr_grp);
+		if (!l_genl_attr_recurse(attr, &attr_grp))
+			continue;
 
 		while (l_genl_attr_next(&attr_grp, &type, &len, &data))
{
 			switch (type) {