Minor bug fix in libprocess, as well as moving some assert statements over to CHECK from glog.
Minor bug fix in libprocess, as well as moving some assert statements over to CHECK from glog.

charlescearl/VirtualMesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos