after building the library you have to import it in eclipse
File -> New -> Other... -> Android -> Android Project from Existing Code -> Browse_your_project
Now open your application (Project which have activity) and assign linphone library which you have earlier loaded....
Right click on your project -> select Android tab from left hand side -> from the bottom library section, click on "Add..." -> you will see the listed library which you have in your eclipse workspace -> select correct one -> click "OK" -> now refresh and clean the project -> build and try to run