Fix memory leak in print_searchpaths()

Fix memory leak in print_searchpaths()

==175453== 522 bytes in 8 blocks are definitely lost in loss record 2,923 of 3,201
==175453==    at 0x4C2EBAB: malloc (vg_replace_malloc.c:299)
==175453==    by 0x59E9BB5: PyObject_Malloc (in /usr/lib64/libpython3.6m.so.1.0)
==175453==    by 0x5A35A76: PyBytes_FromStringAndSize (in /usr/lib64/libpython3.6m.so.1.0)
==175453==    by 0x4E3FA6E: print_searchpaths (srd.c:173)
==175453==    by 0x4E3FA6E: srd_init (srd.c:287)
==175453==    by 0x4034BE: test_session_reset_nodata (session.c:238)
==175453==    by 0x53E51D5: srunner_run_tagged (in /usr/lib64/libcheck.so.0.0.0)
==175453==    by 0x401237: main (main.c:51)