bpf: Initialize ret to 0 inside btf_populate_kfunc_set()

Kernel test robot reported below error ->

kernel/bpf/btf.c:6718 btf_populate_kfunc_set()
error: uninitialized symbol 'ret'.

Initialize ret to 0.

Fixes: dee872e ("bpf: Populate kfunc BTF ID sets in struct btf")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Souptick Joarder (HPE) <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Kumar Kartikeya Dwivedi <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: Souptick Joarder (HPE)

kernel/bpf/btf.c

@@ -6706,7 +6706,7 @@ static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
 				  const struct btf_kfunc_id_set *kset)
 {
 	bool vmlinux_set = !btf_is_module(btf);
-	int type, ret;
+	int type, ret = 0;
 
 	for (type = 0; type < ARRAY_SIZE(kset->sets); type++) {
 		if (!kset->sets[type])