profil01: don't use address of function

This testcase is failing on ppc64 BE system, because
address of &test_profil does not reference beginning of code,
but entry in .opd section:
  "This section contains the official procedure descriptors.
   A pointer to a function shall reference a procedure descriptor
   in this section."
which was at address larger than all .text of test_profil.

This patch is replacing address of function approach with gcc's
__builtin_return_address() to get current pc value.

Signed-off-by: Jan Stancek <jstancek@redhat.com>