[PATCH v2] docs: networking: Add title caret and missing doc

[Adam Zerella <adam.zerella@gmail.com>]

Resolving a couple of Sphinx documentation warnings
that are generated in the networking section.

- WARNING: document isn't included in any toctree
- WARNING: Title underline too short.

Signed-off-by: Adam Zerella <adam.zerella@gmail.com>
---

v2: Moved 'netronome/nfp' into alphabetical order
---
 Documentation/networking/device_drivers/index.rst | 1 +
 Documentation/networking/j1939.rst                | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/device_drivers/index.rst b/Documentation/networking/device_drivers/index.rst
index f51f92571e39..c1f7f75e5fd9 100644
--- a/Documentation/networking/device_drivers/index.rst
+++ b/Documentation/networking/device_drivers/index.rst
@@ -23,6 +23,7 @@ Contents:
    intel/ice
    google/gve
    mellanox/mlx5
+   netronome/nfp
    pensando/ionic
 
 .. only::  subproject and html
diff --git a/Documentation/networking/j1939.rst b/Documentation/networking/j1939.rst
index ce7e7a044e08..dc60b13fcd09 100644
--- a/Documentation/networking/j1939.rst
+++ b/Documentation/networking/j1939.rst
@@ -272,7 +272,7 @@ supported flags are:
 * MSG_DONTWAIT, i.e. non-blocking operation.
 
 recvmsg(2)
-^^^^^^^^^
+^^^^^^^^^^
 
 In most cases recvmsg(2) is needed if you want to extract more information than
 recvfrom(2) can provide. For example package priority and timestamp. The
-- 
2.21.0