Fix a warning for a variable shadowed in the tests

Just a nitpick, but there are a couple of the variables
shadowed in the list comprehensions in the tests.
It doesn't compromise the tests, but raises a warning
during the tests' build.
diff --git a/src/couch_epi_plugin.erl b/src/couch_epi_plugin.erl
index 0d76465..133a0d2 100644
--- a/src/couch_epi_plugin.erl
+++ b/src/couch_epi_plugin.erl
@@ -240,8 +240,8 @@
     ],
 
     Defs = definitions(providers, bar_handlers),
-    Result = [{App, V} || {App, #couch_epi_spec{value = V}} <- Defs],
-    Tests = lists:zip(Expected, Result),
+    Results = [{App, V} || {App, #couch_epi_spec{value = V}} <- Defs],
+    Tests = lists:zip(Expected, Results),
     [?assertEqual(Expect, Result) || {Expect, Result} <- Tests],
     ok.
 
@@ -254,8 +254,8 @@
     ],
     AllDefs = grouped_definitions([foo_epi, bar_epi]),
     {_, Defs} = lists:keyfind({providers, bar_handlers}, 1, AllDefs),
-    Result = [{App, V} || {App, #couch_epi_spec{value = V}} <- Defs],
-    Tests = lists:zip(Expected, Result),
+    Results = [{App, V} || {App, #couch_epi_spec{value = V}} <- Defs],
+    Tests = lists:zip(Expected, Results),
     [?assertEqual(Expect, Result) || {Expect, Result} <- Tests],
     ok.