fix check-dialyzer script to properly fix full path (2600hz#6102)

For kazoo apps repo, we use the full path as changed file, and pass
that to check_dialyzer script. But that script is not properly
converting the erl file path (full path) to correct ebin
file (dropping the leading "/" from the beginning) causing to not
dialyze anything at all.

scripts/check-dialyzer.escript

@@ -89,6 +89,12 @@ is_beam(Path) ->
 is_ebin_dir(Path) ->
     "ebin" == filename:basename(Path).
 
+root_dir("/"++Path) ->
+    filename:join(["/" | lists:takewhile(fun is_not_src/1
+                                        ,string:tokens(Path, "/")
+                                        )
+                  ]
+                 );
 root_dir(Path) ->
     filename:join(lists:takewhile(fun is_not_src/1
                                  ,string:tokens(Path, "/")