Fix -Asserts warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101191 91177308-0d34-0410-b5e6-96231b3b80d8

utils/unittest/googletest/include/gtest/internal/gtest-linked_ptr.h

@@ -176,6 +176,7 @@ class linked_ptr {
   // Sole ownership by this linked_ptr object is required.
   T* release() {
     bool last = link_.depart();
+    (void) last;
     assert(last);
     T* v = value_;
     value_ = NULL;