Issue #3080: Remove unused argument of _PyImport_GetDynLoadFunc()

The first argument, fqname, was not used.
diff --git a/Python/dynload_os2.c b/Python/dynload_os2.c
index 101c024..f7264da 100644
--- a/Python/dynload_os2.c
+++ b/Python/dynload_os2.c
@@ -15,7 +15,7 @@
     {0, 0}
 };
 
-dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
+dl_funcptr _PyImport_GetDynLoadFunc(const char *shortname,
                                     const char *pathname, FILE *fp)
 {
     dl_funcptr p;