patch 8.1.2173: searchit() has too many arguments

Problem:    Searchit() has too many arguments.
Solution:   Move optional arguments to a struct.  Add the "wrapped" argument.
diff --git a/src/insexpand.c b/src/insexpand.c
index 644542e..31b952b 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -2881,7 +2881,7 @@
 		    found_new_match = searchit(NULL, ins_buf, pos, NULL,
 							      compl_direction,
 				 compl_pattern, 1L, SEARCH_KEEP + SEARCH_NFMSG,
-					     RE_LAST, (linenr_T)0, NULL, NULL);
+								RE_LAST, NULL);
 		--msg_silent;
 		if (!compl_started || set_match_pos)
 		{