patch 8.2.3787: no proper formatting of a C line comment after a statement

Problem:    No proper formatting of a C line comment after a statement.
Solution:   Find the start of the line comment, insert the comment leader and
            indent the comment properly.
diff --git a/src/normal.c b/src/normal.c
index d3c4c78..2d75548 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -6511,7 +6511,7 @@
 		       ) == OK
 		&& open_line(cap->cmdchar == 'O' ? BACKWARD : FORWARD,
 			 has_format_option(FO_OPEN_COMS) ? OPENLINE_DO_COM : 0,
-								      0) == OK)
+								0, NULL) == OK)
 	{
 #ifdef FEAT_CONCEAL
 	    if (curwin->w_p_cole > 0 && oldline != curwin->w_cursor.lnum)