SyscallStub: fix a potential crash due to the removal of self.resolves.
SyscallStub: fix a potential crash due to the removal of self.resolves.

angr/angr,axt/angr,schieb/angr,angr/angr,f-prettyland/angr,chubbymaggie/angr,schieb/angr,iamahuman/angr,chubbymaggie/angr,chubbymaggie/angr,schieb/angr,iamahuman/angr,axt/angr,tyb0807/angr,axt/angr,tyb0807/angr,angr/simuvex,tyb0807/angr,iamahuman/angr,f-prettyland/angr,angr/angr,f-prettyland/angr