doc: output correct --help references with --program-prefix

* src/system.h (emit_ancillary_info): Take the invariant PROGRAM_NAME
as a parameter, so that consistent references are made to online docs
and texinfo nodes, when a --program-prefix is in place.  Note the
man pages don't need this fix as they're generated before the program
prefix is used.
* NEWS: Mention the improvements in references to online documentation.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/ln.c b/src/ln.c
index 5140e92dc..ce812cc61 100644
--- a/src/ln.c
+++ b/src/ln.c
@@ -452,7 +452,7 @@ the VERSION_CONTROL environment variable.  Here are the values:\n\
 Using -s ignores -L and -P.  Otherwise, the last option specified controls\n\
 behavior when a TARGET is a symbolic link, defaulting to %s.\n\
 "), LINK_FOLLOWS_SYMLINKS ? "-L" : "-P");
-      emit_ancillary_info ();
+      emit_ancillary_info (PROGRAM_NAME);
     }
   exit (status);
 }