test: rename file_delete to file_delete_internal in new test functions

Author: andinux

test/unit.c

@@ -2800,7 +2800,7 @@ bool do_test_merge_check_db_version (int nclients, bool print_result, bool clean
         if (cleanup_databases) {
             char buf[256];
             do_build_database_path(buf, i, timestamp, saved_counter);
-            file_delete(buf);
+            file_delete_internal(buf);
         }
     }
     return result;
@@ -2906,7 +2906,7 @@ bool do_test_merge_check_db_version_2 (int nclients, bool print_result, bool cle
         if (cleanup_databases) {
             char buf[256];
             do_build_database_path(buf, i, timestamp, saved_counter);
-            file_delete(buf);
+            file_delete_internal(buf);
         }
     }
     return result;
@@ -2980,7 +2980,7 @@ bool do_test_insert_cloudsync_changes (bool print_result, bool cleanup_databases
     if (cleanup_databases) {
         char buf[256];
         do_build_database_path(buf, 0, timestamp, saved_counter);
-        file_delete(buf);
+        file_delete_internal(buf);
     }
     return result;
 }