shelve: fix a missing variable in the exception handler for delete

Caught by pytype.  I haven't paid much attention to the progress of this
extension, but I *think* this was the intent.

Differential Revision: https://phab.mercurial-scm.org/D7457

mercurial/shelve.py

@@ -603,8 +603,8 b' def deletecmd(ui, repo, pats):'
     if not pats:
         raise error.Abort(_(b'no shelved changes specified!'))
     with repo.wlock():
+        for name in pats:
         try:
-            for name in pats:
                 for suffix in shelvefileextensions:
                     shfile = shelvedfile(repo, name, suffix)
                     # patch file is necessary, as it should
@@ -614,11 +614,11 b' def deletecmd(ui, repo, pats):'
                     # bundle
                     if shfile.exists() or suffix == patchextension:
                         shfile.movetobackup()
-            cleanupoldbackups(repo)
         except OSError as err:
             if err.errno != errno.ENOENT:
                 raise
             raise error.Abort(_(b"shelved change '%s' not found") % name)
+            cleanupoldbackups(repo)
 
 
 def listshelves(repo):