Fix Coverity issues

Fix Coverity issues

- sensor_is_supported() has a return value, int type.
  In tilt-sensor-impl-tizen.cpp, there is an omitted return check code
  at 146 line. So, added to check the return value of sensor_is_supported.

- Fixed to memory leak in clipboard-impl-ecore-wl.
  Variable 'reply' is allocated from 'eldbus_proxy_send_and_block()'
  So, added to eldbus_message_unref(reply) for memory free.

Change-Id: I9a389508430d3b209e886f3dc83e7898350b92e0
Signed-off-by: Seoyeon Kim <seoyeon2.kim@samsung.com>