bpf: Use kvmemdup to simplify the code

Use kvmemdup instead of kvmalloc() + memcpy() to simplify the
code.

No functional change intended.
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://lore.kernel.org/r/20240828062128.1223417-1-lihongbo22@huawei.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

kernel/bpf/btf.c

@@ -6272,12 +6272,11 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
 	btf->kernel_btf = true;
 	snprintf(btf->name, sizeof(btf->name), "%s", module_name);
 
-	btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN);
+	btf->data = kvmemdup(data, data_size, GFP_KERNEL | __GFP_NOWARN);
 	if (!btf->data) {
 		err = -ENOMEM;
 		goto errout;
 	}
-	memcpy(btf->data, data, data_size);
 	btf->data_size = data_size;
 
 	err = btf_parse_hdr(env);