patch 8.0.1135: W_WINCOL() is always the same

Problem:    W_WINCOL() is always the same.
Solution:   Expand the macro.
diff --git a/src/terminal.c b/src/terminal.c
index 9b5e4ce..18a0e61 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -730,7 +730,7 @@
     VTermModifier   mod = VTERM_MOD_NONE;
 
     vterm_mouse_move(vterm, mouse_row - W_WINROW(curwin),
-					    mouse_col - W_WINCOL(curwin), mod);
+					    mouse_col - curwin->w_wincol, mod);
     vterm_mouse_button(vterm, button, pressed, mod);
     return TRUE;
 }
@@ -1308,7 +1308,7 @@
 	case K_MOUSERIGHT:
 	    if (mouse_row < W_WINROW(curwin)
 		    || mouse_row >= (W_WINROW(curwin) + curwin->w_height)
-		    || mouse_col < W_WINCOL(curwin)
+		    || mouse_col < curwin->w_wincol
 		    || mouse_col >= W_ENDCOL(curwin)
 		    || dragging_outside)
 	    {