update format of doxygen

Change-Id: I52abc25afb46df4ac010b5251b123a6c1be2434b
diff --git a/tests/identity-management-fixture.hpp b/tests/identity-management-fixture.hpp
index a45e9d0..9b10dbf 100644
--- a/tests/identity-management-fixture.hpp
+++ b/tests/identity-management-fixture.hpp
@@ -64,8 +64,8 @@
 
   /**
    *  @brief Save identity certificate to a file
-   *  @p identity identity
-   *  @p filename file name, should be writable
+   *  @param identity identity
+   *  @param filename file name, should be writable
    *  @return whether successful
    */
   bool