Use explicit scope in all ale_linters

vint -s is now clean

ale_linters/html/htmlhint.vim

@@ -11,33 +11,33 @@ function! ale_linters#html#htmlhint#Handle(buffer, lines) abort
     " Matches patterns lines like the following:
     "stdin:7:10: <title></title> must not be empty. [error/title-require]
 
-    let pattern = '^stdin:\(\d\+\):\(\d\+\): \(.\+\)$'
-    let output = []
+    let l:pattern = '^stdin:\(\d\+\):\(\d\+\): \(.\+\)$'
+    let l:output = []
 
-    for line in a:lines
-        let match = matchlist(line, pattern)
+    for l:line in a:lines
+        let l:match = matchlist(l:line, l:pattern)
 
-        if len(match) == 0
+        if len(l:match) == 0
             continue
         endif
 
-        let line = match[1] + 0
-        let col = match[2] + 0
-        let text = match[3]
+        let l:line = l:match[1] + 0
+        let l:col = l:match[2] + 0
+        let l:text = l:match[3]
 
         " 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,
+        \   'col': l:col,
+        \   'text': l:text,
         \   'type': 'E',
         \   'nr': -1,
         \})
     endfor
 
-    return output
+    return l:output
 endfunction
 
 call ale#linter#Define('html', {