Fix (harmless) memory leak found by memcheck.

llvm-svn: 95862
diff --git a/llvm/unittests/ADT/StringMapTest.cpp b/llvm/unittests/ADT/StringMapTest.cpp
index 3dcdc39..413f068 100644
--- a/llvm/unittests/ADT/StringMapTest.cpp
+++ b/llvm/unittests/ADT/StringMapTest.cpp
@@ -191,6 +191,7 @@
           testKeyFirst, testKeyFirst + testKeyLength, 1u);
   EXPECT_STREQ(testKey, entry->first());
   EXPECT_EQ(1u, entry->second);
+  free(entry);
 }
 
 // Test insert() method.