commands.bookmarks: move hexfn to inside list block This isn't used outside this block, nor is it expected to be.

commands.bookmarks: move cur initialization to inside wlock This is more correct because we now fetch '.' while nothing else can interfere with it.

commands.bookmarks: pass cur in explicitly to checkconflict cur will be moved inside the wlock in a future patch, so we need to pass it into checkconflict explicitly.

commands.bookmarks: hold wlock for write operations Any invocations of bookmarks other than a plain 'hg bookmarks' will likely cause a write to the bookmark store. These should be guarded by the wlock. The repo._bookmarks read should be similarly guarded by the wlock if we're going to be subsequently writing to it.