Fix luacheck

test/integration/expel_last_instance_test.lua

@@ -30,7 +30,7 @@ g.before_all(function()
     -- wait until all buckets are created
     t.helpers.retrying({}, function()
         local count = g.to_be_expelled:exec(function()
-            return vshard.storage.buckets_count()
+            return _G.vshard.storage.buckets_count()
         end)
         t.assert_equals(count, 1500)
     end)
@@ -39,10 +39,10 @@ g.before_all(function()
         -- this fiber will exit if the bucket count is decreased
         -- we'll need that to check alerts later
         local fiber = require('fiber')
-        local before_count = vshard.storage.buckets_count()
+        local before_count = _G.vshard.storage.buckets_count()
         fiber.create(function()
             while true do
-                if vshard.storage.buckets_count() < before_count then
+                if _G.vshard.storage.buckets_count() < before_count then
                     os.exit(0)
                 end
                 fiber.sleep(0.1)
@@ -111,7 +111,7 @@ function g.test_expel()
 
     t.helpers.retrying({timeout = 10}, function()
         local count = g.to_be_expelled:exec(function()
-            return vshard.storage.buckets_count()
+            return _G.vshard.storage.buckets_count()
         end)
         t.assert_equals(count, 0)
     end)