Fixed typo in wine_get_unix_file_name().

diff --git a/files/dos_fs.c b/files/dos_fs.c
index 2aa9b8b..6860b57 100644
--- a/files/dos_fs.c
+++ b/files/dos_fs.c
@@ -1376,7 +1376,7 @@
 {
     BOOL ret;
     DOS_FULL_NAME path;
-    if ((ret = DOSFS_GetFullName( dos, FALSE, &path ))) lstrcpynA( buffer, dos, len );
+    if ((ret = DOSFS_GetFullName( dos, FALSE, &path ))) lstrcpynA( buffer, path.long_name, len );
     return ret;
 }