vlib: fix vlib_pci_get_device_info on when not running as root

While comment properly says that only first 64 bytes can be read, actual
code was returning error instead being happy with 64 bytes received.

Change-Id: I09c0d1d5c9fc8e1f6c59c093d81bb1ce1924281b
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vlib/linux/pci.c b/src/vlib/linux/pci.c
index 8954bcc..e67e651 100644
--- a/src/vlib/linux/pci.c
+++ b/src/vlib/linux/pci.c
@@ -182,10 +182,8 @@
 
   /* You can only read more that 64 bytes of config space as root; so we try to
      read the full space but fall back to just the first 64 bytes. */
-  if (read (fd, &di->config_data, sizeof (di->config_data)) !=
-      sizeof (di->config_data)
-      && read (fd, &di->config0,
-	       sizeof (di->config0)) != sizeof (di->config0))
+  if (read (fd, &di->config_data, sizeof (di->config_data)) <
+      sizeof (di->config0))
     {
       err = clib_error_return_unix (0, "read `%s'", f);
       close (fd);