Merge pull request #1443 from iovisor/yhs_dev

use user-provided log_level in bpf_prog_load

src/cc/libbpf.c

@@ -448,6 +448,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type, const char *name,
     if (tmp_log_buf)
       free(tmp_log_buf);
     tmp_log_buf_size = LOG_BUF_SIZE;
+    if (attr.log_level == 0)
       attr.log_level = 1;
     for (;;) {
       tmp_log_buf = malloc(tmp_log_buf_size);