patch 8.2.4241: some type casts are redundant

Problem:    Some type casts are redundant.
Solution:   Remove the type casts. (closes #9643)
diff --git a/src/buffer.c b/src/buffer.c
index e50b01d..24da829 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1624,7 +1624,7 @@
 	    // also be deleted, etc.
 	    if (bnr == curbuf->b_fnum)
 		do_current = bnr;
-	    else if (do_buffer_ext(command, DOBUF_FIRST, FORWARD, (int)bnr,
+	    else if (do_buffer_ext(command, DOBUF_FIRST, FORWARD, bnr,
 			  DOBUF_NOPOPUP | (forceit ? DOBUF_FORCEIT : 0)) == OK)
 		++deleted;
 
@@ -3754,7 +3754,7 @@
     }
     else
     {
-	p = (char *)msg_trunc_attr(buffer, FALSE, 0);
+	p = msg_trunc_attr(buffer, FALSE, 0);
 	if (restart_edit != 0 || (msg_scrolled && !need_wait_return))
 	    // Need to repeat the message after redrawing when:
 	    // - When restart_edit is set (otherwise there will be a delay