Remove accidental use of a feature that doesn't exist in CMake 3.5

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 001db80..b3308cb 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -161,9 +161,10 @@
 list(REMOVE_DUPLICATES test_suites)
 list(SORT test_suites)
 foreach(test_suite ${test_suites})
-    get_filename_component(data_name ${test_suite} NAME_WLE)
-    string(REPLACE "test_suite_" "" data_name ${data_name})
-    string(REGEX MATCH "[^.]*" function_name ${data_name})
+    get_filename_component(data_name ${test_suite} NAME)
+    string(REGEX REPLACE "\.data$" "" data_name "${data_name}")
+    string(REPLACE "test_suite_" "" data_name "${data_name}")
+    string(REGEX MATCH "[^.]*" function_name "${data_name}")
     add_test_suite(${function_name} ${data_name})
 endforeach(test_suite)