patch 9.0.0758: "precedes" from 'listchars' overwritten by <<<

Problem:    "precedes" from 'listchars' overwritten by <<< for 'smoothscroll'.
Solution:   Keep the "precedes" character.
diff --git a/src/drawline.c b/src/drawline.c
index f3024c2..8824a01 100644
--- a/src/drawline.c
+++ b/src/drawline.c
@@ -766,9 +766,11 @@
 {
     if (wlv->row == 0 && wp->w_skipcol > 0
 #if defined(FEAT_LINEBREAK)
+	    // do not overwrite the 'showbreak' text with "<<<"
 	    && *get_showbreak_value(wp) == NUL
 #endif
-	    )
+	    // do not overwrite the 'listchars' "precedes" text with "<<<"
+	    && !(wp->w_p_list && wp->w_lcs_chars.prec != 0))
     {
 	int off = (int)(current_ScreenLine - ScreenLines);
 	int skip = 0;