viewport: Cleanup setting parent and more log

viewport: Cleanup setting parent and more log

The crash happened as the backtrace shown below but I couldn't find the
cause. So, this patch logs more about viewport to help find the cause of
problem next time if it will happen again.

backtrace:
 (gdb)bt
 #0  0x000d6e98 in e_object_is_del (obj=0x6) at /usr/src/debug/enlightenment-0.20.0/src/bin/e_object.c:106
 #1  0x00086088 in _e_comp_wl_viewport_cb_parent_show (data=0x1d50c70, e=<optimized out>, obj=<optimized out>, event_info=<optimized out>) at /usr/src/debug/enlightenment-0.20.0/src/bin/e_comp_wl_viewport.c:572
 #2  0xb5d91df6 in _eo_evas_object_cb (data=0x207e4c8, event=<optimized out>) at /usr/src/debug/efl-1.25.1/builddir/../src/lib/evas/canvas/evas_callbacks.c:181
 ...

Change-Id: I7be6210c608ca02d55d59a6c65c60a8bb04873ba