[PATCH for bpf-next] docs: bpf: add minimal markup to address doc warning

[Lukas Bulwahn <lukas.bulwahn@gmail.com>]

Commit 91c960b00566 ("bpf: Rename BPF_XADD and prepare to encode other
atomics in .imm") modified the BPF documentation, but missed some ReST
markup.

Hence, make htmldocs warns on Documentation/networking/filter.rst:1053:

  WARNING: Inline emphasis start-string without end-string.

Add some minimal markup to address this warning.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
---
applies cleanly on next-20210118

Brendan, please ack.

Alexei, please pick this minor cleanup patch on your bpf-next.

 Documentation/networking/filter.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/filter.rst b/Documentation/networking/filter.rst
index f6d8f90e9a56..45f6fde1776c 100644
--- a/Documentation/networking/filter.rst
+++ b/Documentation/networking/filter.rst
@@ -1048,12 +1048,12 @@ Unlike classic BPF instruction set, eBPF has generic load/store operations::
 Where size is one of: BPF_B or BPF_H or BPF_W or BPF_DW.
 
 It also includes atomic operations, which use the immediate field for extra
-encoding.
+encoding::
 
    .imm = BPF_ADD, .code = BPF_ATOMIC | BPF_W  | BPF_STX: lock xadd *(u32 *)(dst_reg + off16) += src_reg
    .imm = BPF_ADD, .code = BPF_ATOMIC | BPF_DW | BPF_STX: lock xadd *(u64 *)(dst_reg + off16) += src_reg
 
-The basic atomic operations supported are:
+The basic atomic operations supported are::
 
     BPF_ADD
     BPF_AND
-- 
2.17.1