isl_union_*_alloc: plug memory leak on error path
isl_union_*_alloc: plug memory leak on error path

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

nicolasvasilache/isl,KangDroidSMProject/ISL,KangDroidSMProject/ISL,nicolasvasilache/isl,BobSaget-Mod/libisl,KangDroidSMProject/ISL,tobig/isl,inducer/isl-mirror,crossbuild/isl,abduld/isl,tobig/isl,crossbuild/isl,BenzoSM/isl,Meinersbur/isl,evaautomation/isl,Distrotech/isl,Distrotech/isl,BenzoSM/isl,nicolasvasilache/isl,abduld/isl,abduld/isl,Distrotech/isl,SaberMod/isl-current,PollyLabs/isl,simbuerg/isl,KangDroidSMProject/ISL,evaautomation/isl,nicolasvasilache/isl,nicolasvasilache/isl,UBERTC/isl,BenzoSM/isl,simbuerg/isl,jleben/isl,BobSaget-Mod/libisl,PollyLabs/isl,Meinersbur/isl,Distrotech/isl,simbuerg/isl,BobSaget-Mod/libisl,abduld/isl,inducer/isl-mirror,PollyLabs/isl,tobig/isl,evaautomation/isl,inducer/isl-mirror,UBERTC/isl,KangDroidSMProject/ISL,BobSaget-Mod/libisl,PollyLabs/isl,inducer/isl-mirror,inducer/isl-mirror,SaberMod/isl-current,Meinersbur/isl,evaautomation/isl,BenzoSM/isl,simbuerg/isl,tobig/isl,SaberMod/isl-current,BenzoSM/isl,Meinersbur/isl,jleben/isl,jleben/isl,jleben/isl,crossbuild/isl,jleben/isl,crossbuild/isl,BobSaget-Mod/libisl,PollyLabs/isl,simbuerg/isl,Distrotech/isl,UBERTC/isl,SaberMod/isl-current,UBERTC/isl