patch 8.2.3022: available encryption methods are not strong enough

Problem:    Available encryption methods are not strong enough.
Solution:   Add initial support for xchaha20. (Christian Brabandt,
            closes #8394)
diff --git a/src/blowfish.c b/src/blowfish.c
index 342bcc4..4502a1c 100644
--- a/src/blowfish.c
+++ b/src/blowfish.c
@@ -596,7 +596,8 @@
     cryptstate_T *state,
     char_u	*from,
     size_t	len,
-    char_u	*to)
+    char_u	*to,
+    int		last UNUSED)
 {
     bf_state_T *bfs = state->method_state;
     size_t	i;
@@ -619,7 +620,8 @@
     cryptstate_T *state,
     char_u	*from,
     size_t	len,
-    char_u	*to)
+    char_u	*to,
+    int		last UNUSED)
 {
     bf_state_T *bfs = state->method_state;
     size_t	i;
@@ -680,5 +682,4 @@
     }
     return OK;
 }
-
 #endif // FEAT_CRYPT