[PATCH] bpf: libbpf: eliminate Docum. warnings in libbpf_naming_convention

Use "code-block: none" instead of "c" for non-C-language code blocks.
Removes these warnings:

lnx-514-rc4/Documentation/bpf/libbpf/libbpf_naming_convention.rst:111: WARNING: Could not lex literal_block as "c". Highlighting skipped.
lnx-514-rc4/Documentation/bpf/libbpf/libbpf_naming_convention.rst:124: WARNING: Could not lex literal_block as "c". Highlighting skipped.

Fixes: f42cfb469f9b ("bpf: Add documentation for libbpf including API autogen")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Grant Seltzer <redacted>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: bpf@vger.kernel.org
---
 Documentation/bpf/libbpf/libbpf_naming_convention.rst |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- lnx-514-rc4.orig/Documentation/bpf/libbpf/libbpf_naming_convention.rst
+++ lnx-514-rc4/Documentation/bpf/libbpf/libbpf_naming_convention.rst

@@ -108,7 +108,7 @@ This bump in ABI version is at most once
 
 For example, if current state of ``libbpf.map`` is:
 
-.. code-block:: c
+.. code-block:: none
 
         LIBBPF_0.0.1 {
         	global:

@@ -121,7 +121,7 @@ For example, if current state of ``libbp
 , and a new symbol ``bpf_func_c`` is being introduced, then
 ``libbpf.map`` should be changed like this:
 
-.. code-block:: c
+.. code-block:: none
 
         LIBBPF_0.0.1 {
         	global: