patch 8.0.0882: term_scrape() and term_getline() require two arguments

Problem:    term_scrape() and term_getline() require two arguments but it is
            not enforced.
Solution:   Correct minimal number of arguments. (Hirohito Higashi)  Update
            documentation. (Ken Takata)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index aa8b140..fde2058 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -834,13 +834,13 @@
     {"term_getattr",	2, 2, f_term_getattr},
     {"term_getcursor",	1, 1, f_term_getcursor},
     {"term_getjob",	1, 1, f_term_getjob},
-    {"term_getline",	1, 2, f_term_getline},
+    {"term_getline",	2, 2, f_term_getline},
     {"term_getsize",	1, 1, f_term_getsize},
     {"term_getstatus",	1, 1, f_term_getstatus},
     {"term_gettitle",	1, 1, f_term_gettitle},
     {"term_gettty",	1, 1, f_term_gettty},
     {"term_list",	0, 0, f_term_list},
-    {"term_scrape",	1, 2, f_term_scrape},
+    {"term_scrape",	2, 2, f_term_scrape},
     {"term_sendkeys",	2, 2, f_term_sendkeys},
     {"term_start",	1, 2, f_term_start},
     {"term_wait",	1, 1, f_term_wait},