Use explicit scope in all ale_linters

vint -s is now clean

ale_linters/yaml/yamllint.vim

@@ -10,34 +10,34 @@ function! ale_linters#yaml#yamllint#Handle(buffer, lines)
     " Matches patterns line the following:
     " something.yaml:1:1: [warning] missing document start "---" (document-start)
     " something.yml:2:1: [error] syntax error: expected the node content, but found '<stream end>'
-    let pattern = '^.*:\(\d\+\):\(\d\+\): \[\(error\|warning\)\] \(.\+\)$'
-    let output = []
+    let l:pattern = '^.*:\(\d\+\):\(\d\+\): \[\(error\|warning\)\] \(.\+\)$'
+    let l:output = []
 
-    for line in a:lines
-        let l:match = matchlist(line, pattern)
+    for l:line in a:lines
+        let l:match = matchlist(l:line, l:pattern)
 
         if len(l:match) == 0
             continue
         endif
 
-        let line = match[1] + 0
-        let col = match[2] + 0
-        let type = match[3]
-        let text = match[4]
+        let l:line = l:match[1] + 0
+        let l:col = l:match[2] + 0
+        let l:type = l:match[3]
+        let l:text = l:match[4]
 
         " vcol is Needed to indicate that the column is a character.
-        call add(output, {
+        call add(l:output, {
         \   'bufnr': a:buffer,
-        \   'lnum': line,
+        \   'lnum': l:line,
         \   'vcol': 0,
-        \   'col': col,
-        \   'text': text,
-        \   'type': type ==# 'warning' ? 'W' : 'E',
+        \   'col': l:col,
+        \   'text': l:text,
+        \   'type': l:type ==# 'warning' ? 'W' : 'E',
         \   'nr': -1,
         \})
     endfor
 
-    return output
+    return l:output
 endfunction
 
 call ale#linter#Define('yaml', {