tests: avoid memory leak on testTLSSessionInit
tests: avoid memory leak on testTLSSessionInit

* tests/virnettlscontexttest: fix memory leak on virnettlscontext test case.

* Detected in valgrind run:

==25667==
==25667== 86,651 (34,680 direct, 51,971 indirect) bytes in 10 blocks are
definitely lost in loss record 350 of 351
==25667==    at 0x4005447: calloc (vg_replace_malloc.c:467)
==25667==    by 0x4F1F515D: gnutls_init (gnutls_state.c:270)
==25667==    by 0x8053432: virNetTLSSessionNew (virnettlscontext.c:1181)
==25667==    by 0x804DD24: testTLSSessionInit (virnettlscontexttest.c:624)
==25667==    by 0x804F14D: virtTestRun (testutils.c:140)
==25667==
==25667== 100,578 (38,148 direct, 62,430 indirect) bytes in 11 blocks are
definitely lost in loss record 351 of 351
==25667==    at 0x4005447: calloc (vg_replace_malloc.c:467)
==25667==    by 0x4F1F515D: gnutls_init (gnutls_state.c:270)
==25667==    by 0x8053432: virNetTLSSessionNew (virnettlscontext.c:1181)
==25667==    by 0x804DD3C: testTLSSessionInit (virnettlscontexttest.c:625)
==25667==    by 0x804F14D: virtTestRun (testutils.c:140)

* How to reproduce?
% cd libvirt && ./configure && make && make -C tests valgrind
or
% valgrind -v --leak-check=full ./tests/virnettlscontexttest

Signed-off-by: Alex Jia <e236faec8cb8371bfb245ba3769a84afc9a11438@redhat.com>

jeckersb/libvirt,emaste/libvirt,libvirt/libvirt,taget/libvirt,kantai/libvirt-vfork,dumbbell/libvirt,rmarwaha/libvirt,rmarwaha/libvirt,rlaager/libvirt,danwent/libvirt-ovs,dumbbell/libvirt,VenkatDatta/libvirt,zippy2/libvirt,rmarwaha/libvirt,rmarwaha/libvirt,VenkatDatta/libvirt,leilihh/libvirt,bjzhang/libvirt,warewolf/libvirt,iam-TJ/libvirt,fabianfreyer/libvirt,rmarwaha/libvirt,novel/fbsd-libvirt,cbosdo/libvirt,olafhering/libvirt,kantai/libvirt-vfork,agx/libvirt,leilihh/libvirt,elmarco/libvirt,novel/fbsd-libvirt,danwent/libvirt-ovs,shugaoye/libvirt,datto/libvirt,rmarwaha/libvirt1,iam-TJ/libvirt,leilihh/libvirt,warewolf/libvirt,taget/libvirt,warewolf/libvirt,shugaoye/libvirt,siboulet/libvirt-openvz,novel/fbsd-libvirt,zhlcindy/libvirt-1.1.4-maintain,olafhering/libvirt,zhlcindy/libvirt-1.1.4-maintain,iam-TJ/libvirt,usc-isi/libvirt,emaste/libvirt,jfehlig/libvirt,zippy2/libvirt,taget/libvirt,foomango/libvirt,foomango/libvirt,warewolf/libvirt,wiedi/libvirt,andreabolognani/libvirt,nertpinx/libvirt,rlaager/libvirt,warewolf/libvirt,novel/fbsd-libvirt,shugaoye/libvirt,VenkatDatta/libvirt,jeckersb/libvirt,rmarwaha/libvirt1,usc-isi/libvirt,siboulet/libvirt-openvz,elmarco/libvirt,warewolf/libvirt,agx/libvirt,zhlcindy/libvirt-1.1.4-maintain,novel/fbsd-libvirt,nertpinx/libvirt,eskultety/libvirt,emaste/libvirt,dumbbell/libvirt,fabianfreyer/libvirt,wiedi/libvirt,danwent/libvirt-ovs,crobinso/libvirt,nertpinx/libvirt,iam-TJ/libvirt,soulxu/libvirt-xuhj,siboulet/libvirt-openvz,jardasgit/libvirt,iam-TJ/libvirt,wiedi/libvirt,datto/libvirt,soulxu/libvirt-xuhj,jardasgit/libvirt,leilihh/libvirt,libvirt/libvirt,jardasgit/libvirt,elmarco/libvirt,shugaoye/libvirt,iam-TJ/libvirt,jfehlig/libvirt,jardasgit/libvirt,foomango/libvirt,agx/libvirt,emaste/libvirt,usc-isi/libvirt,dumbbell/libvirt,andreabolognani/libvirt,jardasgit/libvirt,nertpinx/libvirt,wiedi/libvirt,fabianfreyer/libvirt,novel/fbsd-libvirt,trainstack/libvirt,zhlcindy/libvirt-1.1.4-maintain,trainstack/libvirt,fabianfreyer/libvirt,emaste/libvirt,olafhering/libvirt,trainstack/libvirt,taget/libvirt,bjzhang/libvirt,dumbbell/libvirt,trainstack/libvirt,eskultety/libvirt,foomango/libvirt,andreabolognani/libvirt,trainstack/libvirt,siboulet/libvirt-openvz,jfehlig/libvirt,rlaager/libvirt,kantai/libvirt-vfork,crobinso/libvirt,elmarco/libvirt,foomango/libvirt,libvirt/libvirt,agx/libvirt,novel/fbsd-libvirt,libvirt/libvirt,jeckersb/libvirt,leilihh/libvirt,eskultety/libvirt,cbosdo/libvirt,jeckersb/libvirt,zhlcindy/libvirt-1.1.4-maintain,elmarco/libvirt,warewolf/libvirt,bjzhang/libvirt,datto/libvirt,siboulet/libvirt-openvz,danwent/libvirt-ovs,novel/fbsd-libvirt,crobinso/libvirt,bjzhang/libvirt,olafhering/libvirt,crobinso/libvirt,rlaager/libvirt,bjzhang/libvirt,rmarwaha/libvirt1,nertpinx/libvirt,soulxu/libvirt-xuhj,zippy2/libvirt,trainstack/libvirt,novel/fbsd-libvirt,fabianfreyer/libvirt,rlaager/libvirt,iam-TJ/libvirt,VenkatDatta/libvirt,dumbbell/libvirt,cbosdo/libvirt,jeckersb/libvirt,eskultety/libvirt,rmarwaha/libvirt1,soulxu/libvirt-xuhj,andreabolognani/libvirt,agx/libvirt,shugaoye/libvirt,rmarwaha/libvirt1,cbosdo/libvirt,emaste/libvirt,emaste/libvirt,datto/libvirt,andreabolognani/libvirt,kantai/libvirt-vfork,soulxu/libvirt-xuhj,danwent/libvirt-ovs,usc-isi/libvirt,VenkatDatta/libvirt,jeckersb/libvirt,cbosdo/libvirt,eskultety/libvirt,wiedi/libvirt,wiedi/libvirt,leilihh/libvirt,kantai/libvirt-vfork,rmarwaha/libvirt1,jeckersb/libvirt,trainstack/libvirt,taget/libvirt,usc-isi/libvirt,wiedi/libvirt,jfehlig/libvirt,datto/libvirt,zippy2/libvirt,rmarwaha/libvirt