eina - btlog - fix warnign about uninit struct field

sentinel should fill all members to null.

src/bin/eina/eina_btlog/eina_btlog.c

@@ -389,7 +389,7 @@ main(int argc, char **argv)
            .func = _addr2line,
            .prog = "addr2line"
         },
-        { NULL, NULL, NULL } /* Sentinel */
+        { NULL, NULL, NULL, NULL } /* Sentinel */
    };
 
    eina_init();