patch 8.2.4592: search continues after giving E1204

Problem:    Search continues after giving E1204.
Solution:   Return failure after giving E1204. (closes #9972)
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index ed8efcf..4d95f83 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -1653,8 +1653,11 @@
 			    long_u tmp;
 
 			    if (cur)
+			    {
 				semsg(_(e_regexp_number_after_dot_pos_search),
-								 no_Magic(c));
+								  no_Magic(c));
+				return FAIL;
+			    }
 			    tmp = n * 10 + (c - '0');
 
 			    if (tmp < n)