libstdc++: Fix -Wunused-parameter warning in test

	* testsuite/20_util/unsynchronized_pool_resource/allocate.cc: Remove
	name of unused parameter.

libstdc++-v3/ChangeLog

+2020-04-16  Jonathan Wakely  <jwakely@redhat.com>
+
+	* testsuite/20_util/unsynchronized_pool_resource/allocate.cc: Remove
+	name of unused parameter.
+
 2020-04-15  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/bits/fs_dir.h (file_status): Define operator== for C++20.

libstdc++-v3/testsuite/20_util/unsynchronized_pool_resource/allocate.cc

@@ -197,7 +197,7 @@ test06()
     void do_deallocate(void* p, std::size_t bytes, std::size_t align)
     { std::pmr::new_delete_resource()->deallocate(p, bytes, align); }
 
-    bool do_is_equal(const memory_resource& r) const noexcept
+    bool do_is_equal(const memory_resource&) const noexcept
     { return false; }
   };