fix(cfn_lint): Fix cfn-lint arg for stdin (#292)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: jamesoff

doc/CONTRIBUTING.md

@@ -3,7 +3,6 @@
 ## General
 
 - Before committing, please go through the following steps:
-
   1. Lint Lua files with [selene](https://github.com/Kampfkarren/selene)
   2. Format Lua files with [StyLua](https://github.com/JohnnyMorganz/StyLua)
   3. If you've updated documentation, format Markdown files with
@@ -116,7 +115,6 @@ local diagnostic = {
 - If your source can produce project-level diagnostics (i.e. diagnostics for
   more than one file at a time), use the `multiple_files` option described in
   [HELPERS](./HELPERS.md).
-
   - Specify that your source supports project diagnostics in its documentation.
 
   - Make sure each multi-file diagnostic includes either a `filename` or a

lua/null-ls/builtins/diagnostics/cfn_lint.lua

@@ -22,7 +22,7 @@ return h.make_builtin({
     filetypes = { "yaml", "json" },
     generator_opts = {
         command = "cfn-lint",
-        args = { "--format", "parseable", "-" },
+        args = { "--format", "parseable" },
         to_stdin = true,
         from_stderr = true,
         format = "line",