luv_process: ensure handle is not null
luv_process: ensure handle is not null

the handle might have already been closed out, if it is NULL pretend
like nothing happened.

AndrewTsao/luvit,sousoux/luvit,boundary/luvit,GabrielNicolasAvellaneda/luvit-upstream,AndrewTsao/luvit,boundary/luvit,boundary/luvit,luvit/luvit,AndrewTsao/luvit,sousoux/luvit,DBarney/luvit,zhaozg/luvit,zhaozg/luvit,kaustavha/luvit,bsn069/luvit,sousoux/luvit,GabrielNicolasAvellaneda/luvit-upstream,kaustavha/luvit,boundary/luvit,connectFree/lev,DBarney/luvit,GabrielNicolasAvellaneda/luvit-upstream,boundary/luvit,sousoux/luvit,rjeli/luvit,connectFree/lev,rjeli/luvit,boundary/luvit,luvit/luvit,bsn069/luvit,GabrielNicolasAvellaneda/luvit-upstream,DBarney/luvit,sousoux/luvit,rjeli/luvit,sousoux/luvit,rjeli/luvit,kaustavha/luvit,bsn069/luvit,DBarney/luvit