Fix lint warnings: use the full option name

lib/nerdtree/bookmark.vim

@@ -292,7 +292,7 @@ endfunction
 " Get the string that should be rendered in the view for this bookmark
 function! s:Bookmark.str()
     let pathStrMaxLen = winwidth(g:NERDTree.GetWinNum()) - 4 - strdisplaywidth(self.name)
-    if &nu
+    if &number
         let pathStrMaxLen = pathStrMaxLen - &numberwidth
     endif
 

lib/nerdtree/creator.vim

@@ -300,11 +300,11 @@ function! s:Creator._setCommonBufOptions()
     setlocal nowrap
 
     if g:NERDTreeShowLineNumbers
-        setlocal nu
+        setlocal number
     else
-        setlocal nonu
+        setlocal nonumber
         if v:version >= 703
-            setlocal nornu
+            setlocal norelativenumber
         endif
     endif
 
@@ -330,8 +330,8 @@ endfunction
 " FUNCTION: s:Creator._tabpagevar(tabnr, var) {{{1
 function! s:Creator._tabpagevar(tabnr, var)
     let currentTab = tabpagenr()
-    let old_ei = &ei
-    set ei=all
+    let old_ei = &eventignore
+    set eventignore=all
 
     exec 'tabnext ' . a:tabnr
     let v = -1
@@ -340,7 +340,7 @@ function! s:Creator._tabpagevar(tabnr, var)
     endif
     exec 'tabnext ' . currentTab
 
-    let &ei = old_ei
+    let &eventignore = old_ei
 
     return v
 endfunction