Remove imaginary file (#8415)

diff --git a/caffe2/utils/CMakeLists.txt b/caffe2/utils/CMakeLists.txt
index 4d39fa0..90d853c 100644
--- a/caffe2/utils/CMakeLists.txt
+++ b/caffe2/utils/CMakeLists.txt
@@ -5,7 +5,6 @@
         utils/signal_handler.cc
         utils/string_utils.cc
         utils/threadpool/ThreadPool.cc
-        utils/thread_name.cc
         utils/cpuid.cc
         utils/bench_utils.cc
         utils/math_cpu.cc