bpftool: Fix -Wuninitialized-const-pointer warnings with clang >= 21

This fixes the build with -Werror -Wall.

btf_dumper.c:71:31: error: variable 'finfo' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
71 | info.func_info = ptr_to_u64(&finfo);
| ^~~~~

prog.c:2294:31: error: variable 'func_info' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
2294 | info.func_info = ptr_to_u64(&func_info);
|

v2:
- Initialize instead of using memset.

Signed-off-by: Tom Stellard <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
Acked-by: Quentin Monnet <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/bpf/bpftool/btf_dumper.c

···
 	__u32 info_len = sizeof(info);
 	const char *prog_name = NULL;
 	struct btf *prog_btf = NULL;
-	struct bpf_func_info finfo;
+	struct bpf_func_info finfo = {};
 	__u32 finfo_rec_size;
 	char prog_str[1024];
 	int err;

tools/bpf/bpftool/prog.c

···
 
 static char *profile_target_name(int tgt_fd)
 {
-	struct bpf_func_info func_info;
+	struct bpf_func_info func_info = {};
 	struct bpf_prog_info info = {};
 	__u32 info_len = sizeof(info);
 	const struct btf_type *t;