Fix orthography of GetTestLibRoot().

Change-Id: Ib052329b3ebced12a7e2d75b3628b33c7043e0d8
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 5b3eaf8..c27adb6 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -1301,7 +1301,7 @@
 }
 
 TEST(dlfcn, dt_runpath_absolute_path) {
-  std::string libpath = GetTestlibRoot() + "/libtest_dt_runpath_d.so";
+  std::string libpath = GetTestLibRoot() + "/libtest_dt_runpath_d.so";
   void* handle = dlopen(libpath.c_str(), RTLD_NOW);
   ASSERT_TRUE(handle != nullptr) << dlerror();