"ls -l" wouldn't output "+" on SELinux hosts unless -Z was also given.

"ls -l" wouldn't output "+" on SELinux hosts unless -Z was also given.

* src/ls.c (gobble_file): Also get the file context if -l is specified.
Treat getfilecon failures like file_has_acl failures.
(UNKNOWN_SECURITY_CONTEXT): New constant.
(clear_files): Don't free it.
(gobble_file): Set unknown security contexts to it; that way, we
don't have to have special cases for unknown contexts.
(print_long_format, print_file_name_and_frills): Don't worry
about scontext being null, since it's always some string now.