patch 9.0.0206: redraw flags are not named specifically

Problem:    Redraw flags are not named specifically.
Solution:   Prefix "UPD_" to the flags, for UPDate_screen().
diff --git a/src/netbeans.c b/src/netbeans.c
index 5c45279..f9ef19a 100644
--- a/src/netbeans.c
+++ b/src/netbeans.c
@@ -116,7 +116,7 @@
     // remove all signs and update the screen after gutter removal
     coloncmd(":sign unplace *");
     changed_window_setting();
-    update_screen(CLEAR);
+    update_screen(UPD_CLEAR);
     setcursor();
     cursor_on();
     out_flush_cursor(TRUE, FALSE);
@@ -1835,9 +1835,9 @@
 	    }
 
 	    // gui_update_cursor(TRUE, FALSE);
-	    // update_curbuf(NOT_VALID);
+	    // update_curbuf(UPD_NOT_VALID);
 	    update_topline();		// scroll to show the line
-	    update_screen(VALID);
+	    update_screen(UPD_VALID);
 	    setcursor();
 	    cursor_on();
 	    out_flush_cursor(TRUE, FALSE);
@@ -2027,7 +2027,7 @@
 	    args = (char_u *)cp;
 	    coloncmd(":sign unplace %d buffer=%d",
 		     serNum, buf->bufp->b_fnum);
-	    redraw_buf_later(buf->bufp, NOT_VALID);
+	    redraw_buf_later(buf->bufp, UPD_NOT_VALID);
 #endif
 // =====================================================================
 	}
@@ -2113,7 +2113,7 @@
 			}
 		    }
 #endif
-		    redraw_buf_later(buf->bufp, NOT_VALID);
+		    redraw_buf_later(buf->bufp, UPD_NOT_VALID);
 		}
 	    }
 // =====================================================================
@@ -2223,7 +2223,7 @@
      */
     if (buf != NULL && buf->initDone && do_update)
     {
-	update_screen(NOT_VALID);
+	update_screen(UPD_NOT_VALID);
 	setcursor();
 	cursor_on();
 	out_flush_cursor(TRUE, FALSE);
@@ -2528,7 +2528,7 @@
 
     // update the screen after having added the gutter
     changed_window_setting();
-    update_screen(CLEAR);
+    update_screen(UPD_CLEAR);
     setcursor();
     cursor_on();
     out_flush_cursor(TRUE, FALSE);