[nvim] fix: shorten filenames in unfocused buffers

786d119 shortened the filename for the current buffer, but didn't change
the filename in other buffers

.config/nvim/lua/statusline.lua

@@ -215,8 +215,14 @@ local function statusline_focused()
 end
 
 local function statusline_not_focused()
+    local bufnr = vim.fn.winbufnr(vim.g.statusline_winid)
+    local file = vim.fn.expand("#" .. bufnr .. ":p:~")
+    local winwidth = vim.fn.winwidth(0)
     return table.concat {
-        gen_section("%#StatuslineNF#", { "%f", "%m" }),
+        gen_section("%#StatuslineNF#", {
+            shorten_path(file, winwidth / 3),
+            "%m"
+        }),
         "%=",
         gen_section("%#StatuslineNF#", { "%03.p%%" }),
         gen_section("%#StatuslineNF#", { "-%03.c-" })