obslog: use singular name "succnode" for each element of {succnodes}
The name that we pass for formatlist() is the name of each
element. After this patch, you'll write '{succnodes % "{succnode}"}'
instead of the confusing '{succnodes % "{succnodes}"}' (where the two
"succnodes" refer to different things.
Users can write templates that are compatible across this change by
using e.g. '{succnodes % "{if(succnode, succnode, succnodes)}"}'.
{"pattern": "glob:hgext3rd/**/*.py", "tool": "byteify-strings"}