dpkg-gensymbols(1): add kfreebsd-amd64 to the "64bit arches" symbol example

This makes it less likely that this arch will be forgotten when
maintainers copy/paste from the example.

debian/changelog

@@ -50,6 +50,8 @@ dpkg (1.15.4) UNRELEASED; urgency=low
     be installed due to a conflicting file instead of quoting the master link.
   * Add support for extra override file in dpkg-scanpackages. Thanks to Robert
     Millan for the patch. Closes: #537559
+  * Update sample in dpkg-gensymbols(1) to give an accurate listing of
+    64 bit arches. Thanks to Julien Cristau for the patch. Closes: #540382
 
   [ Modestas Vainius ]
   * Provide a meaningful label for dpkg-gensymbols diff.

man/dpkg-gensymbols.1

@@ -144,10 +144,10 @@ in template mode.
 The format of \fIarchitecture list\fR is the same as the one used in the
 \fIBuild-Depends\fR field of \fIdebian/control\fR (except the enclosing
 square brackets []). For example, the first symbol from the list below
-will be considered only on alpha, amd64 and ia64 architectures while the
-second one anywhere except on armel.
+will be considered only on alpha, amd64, kfreebsd-amd64 and ia64 architectures
+while the second one anywhere except on armel.
 
- (arch=alpha amd64 ia64)a_64bit_specific_symbol@Base 1.0
+ (arch=alpha amd64 kfreebsd-amd64 ia64)a_64bit_specific_symbol@Base 1.0
  (arch=!armel)symbol_armel_does_not_have@Base 1.0
 .TP
 .B ignore\-blacklist