isl_coalesce.c: ineq_status_in: improve error handling
isl_coalesce.c: ineq_status_in: improve error handling

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

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