(gud-display-line): Use display-buffer

for GDB-UI as for GUD.

lisp/progmodes/gud.el

@@ -2587,9 +2587,7 @@ Obeying it means displaying in another window the specified file and line."
 	  (with-current-buffer gud-comint-buffer
 	    (gud-find-file true-file)))
 	 (window (and buffer (or (get-buffer-window buffer)
-				 (if (memq gud-minor-mode '(gdbmi gdba))
-				     (gdb-display-source-buffer buffer)
-				   (display-buffer buffer)))))
+				   (display-buffer buffer))))
 	 (pos))
     (if buffer
 	(progn