ecore_imf/wayland: Add NULL check for text_input_manager.

Summary: this patch fixes crash caused by accessing the text_input_manager in wayland_im_context_add().

Test Plan: N/A

Reviewers: jihoon

Reviewed By: jihoon

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D3176

src/modules/ecore_imf/wayland/wayland_module.c

@@ -122,6 +122,9 @@ im_module_create()
                   break;
                }
           }
+
+        if (!text_input_manager)
+          return NULL;
      }
 
    ctxd = wayland_im_context_new(text_input_manager);