[clang-format] Delete a redundant newline at the end of a test case

It slipped in from commit fa6025e.

clang/unittests/Format/FormatTest.cpp

@@ -5019,7 +5019,7 @@ TEST_F(FormatTest, DesignatedInitializers) {
                "             .b = 2,\n"
                "         },\n"
                "     }) {\n"
-               "}\n");
+               "}");
 }
 
 TEST_F(FormatTest, BracedInitializerIndentWidth) {