patch 8.1.0779: argument for message functions is inconsistent

Problem:    Argument for message functions is inconsistent.
Solution:   Make first argument to msg() "char *".
diff --git a/src/ex_eval.c b/src/ex_eval.c
index 10a9dbc..63bca67 100644
--- a/src/ex_eval.c
+++ b/src/ex_eval.c
@@ -556,7 +556,7 @@
 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
 
 	smsg(_("Exception thrown: %s"), excp->value);
-	msg_puts((char_u *)"\n");   /* don't overwrite this either */
+	msg_puts("\n");   /* don't overwrite this either */
 
 	if (debug_break_level > 0 || *p_vfile == NUL)
 	    cmdline_row = msg_row;
@@ -610,7 +610,7 @@
 		    ? _("Exception finished: %s")
 		    : _("Exception discarded: %s"),
 		excp->value);
-	msg_puts((char_u *)"\n");   /* don't overwrite this either */
+	msg_puts("\n");   /* don't overwrite this either */
 	if (debug_break_level > 0 || *p_vfile == NUL)
 	    cmdline_row = msg_row;
 	--no_wait_return;
@@ -679,7 +679,7 @@
 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
 
 	smsg(_("Exception caught: %s"), excp->value);
-	msg_puts((char_u *)"\n");   /* don't overwrite this either */
+	msg_puts("\n");   /* don't overwrite this either */
 
 	if (debug_break_level > 0 || *p_vfile == NUL)
 	    cmdline_row = msg_row;
@@ -806,7 +806,7 @@
     ++no_wait_return;
     msg_scroll = TRUE;		/* always scroll up, don't overwrite */
     smsg(mesg, s);
-    msg_puts((char_u *)"\n");   /* don't overwrite this either */
+    msg_puts("\n");   /* don't overwrite this either */
     cmdline_row = msg_row;
     --no_wait_return;
     if (debug_break_level > 0)