patch 8.2.4725: unused variable in tiny build

Problem:    Unused variable in tiny build.
Solution:   Add #ifdef.
diff --git a/src/normal.c b/src/normal.c
index b5b0448..5634925 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -4197,7 +4197,9 @@
 {
     int		i;
     searchit_arg_T sia;
+#ifdef FEAT_SEARCH_EXTRA
     pos_T	prev_cursor = curwin->w_cursor;
+#endif
 
     cap->oap->motion_type = MCHAR;
     cap->oap->inclusive = FALSE;