selftests/bpf: fix file resource leak in load_kallsyms

FILE pointer variable f is opened but never closed.

Signed-off-by: Peng Hao <[e-mail]>
Signed-off-by: Daniel Borkmann <[e-mail]>

tools/testing/selftests/bpf/trace_helpers.c

···
 		syms[i].name = strdup(func);
 		i++;
 	}
+	fclose(f);
 	sym_cnt = i;
 	qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
 	return 0;