s-s-d: Switch GNU/kFreeBSD systems to use libkvm

Use libkvm instead of relying on linprocfs, which is not the native
procfs on kFreeBSD, and it is usually not mounted as FreeBSD programs
do not expect it to be present.

This stops making the code handle GNU/kFreeBSD as if it was a
Linux-based system.

debian/changelog

@@ -19,6 +19,9 @@ dpkg (1.17.13) UNRELEASED; urgency=low
     Reported by Neil Williams <codehelp@debian.org>.
   * Only test the strerror() compatible code if sys_errlist and sys_nerr
     are present. This fixes a build failure on GNU/Hurd. Closes: #758199
+  * Switch start-stop-daemon on GNU/kFreeBSD systems to use libkvm, instead
+    of relying on linprocfs which is not the native procfs on kFreeBSD, and it
+    is usually not mounted as FreeBSD programs do not expect it to be present.
 
   [ Updated programs translations ]
   * Czech (Miroslav Kure).

debian/control

@@ -13,6 +13,7 @@ Build-Depends: debhelper (>= 7), pkg-config, flex,
  gettext (>= 0.18), po4a (>= 0.41),
  zlib1g-dev, libbz2-dev, liblzma-dev,
  libselinux1-dev (>= 1.28-4) [linux-any],
+ libkvm-dev [kfreebsd-any],
  libncursesw5-dev,
  libtimedate-perl, libio-string-perl
 

utils/start-stop-daemon.c

@@ -25,7 +25,7 @@
 
 #include <dpkg/macros.h>
 
-#if defined(linux) || (defined(__FreeBSD_kernel__) && defined(__GLIBC__))
+#if defined(linux)
 #  define OSLinux
 #elif defined(__GNU__)
 #  define OSHurd
@@ -35,7 +35,7 @@
 #  define OSOpenBSD
 #elif defined(hpux)
 #  define OShpux
-#elif defined(__FreeBSD__)
+#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 #  define OSFreeBSD
 #elif defined(__NetBSD__)
 #  define OSNetBSD