Rename zip_source_win32file.c to zip_source_win32handle.c

To match function names.

lib/CMakeLists.txt

diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index a7ffa99..ae1a298 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -157,7 +157,7 @@
 IF(WIN32)
   SET(LIBZIP_OPSYS_FILES
     zip_source_win32a.c
-    zip_source_win32file.c
+    zip_source_win32handle.c
     zip_source_win32utf8.c
     zip_source_win32w.c
   )