enforce 4.14+ instead of program being present

These two checks are theoretically equivalent,
since netd.o marks the program as requiring 4.14+.

Thus unless netd.o bpf program is broken, or bpfloader
is misbehaving, this change is a no-op.

Bug: 270276754
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I2c6982e7476c2fa56b67532c80d97d7389030d32
diff --git a/netd/BpfHandler.cpp b/netd/BpfHandler.cpp
index 7950ff7..2b773c9 100644
--- a/netd/BpfHandler.cpp
+++ b/netd/BpfHandler.cpp
@@ -93,7 +93,7 @@
     // cgroup if the program is pinned properly.
     // TODO: delete the if statement once all devices should support cgroup
     // socket filter (ie. the minimum kernel version required is 4.14).
-    if (!access(CGROUP_SOCKET_PROG_PATH, F_OK)) {
+    if (bpf::isAtLeastKernelVersion(4, 14, 0)) {
         RETURN_IF_NOT_OK(
                 attachProgramToCgroup(CGROUP_SOCKET_PROG_PATH, cg_fd, BPF_CGROUP_INET_SOCK_CREATE));
     }