all: Allow to build udftools without udev

If udev is not found during configure phase then do not install pktsetup
udev rules file. udev itself is not used for anything else.

Fixes: #30

configure.ac

@@ -25,7 +25,8 @@ AC_C_BIGENDIAN
 AC_SYS_LARGEFILE
 
 PKG_PROG_PKG_CONFIG
-PKG_CHECK_MODULES(UDEV, [udev], [ac_cv_udevdir=`$PKG_CONFIG --variable=udevdir udev`])
+PKG_CHECK_MODULES(UDEV, [udev], [ac_cv_udevdir=`$PKG_CONFIG --variable=udevdir udev`], [ac_cv_udevdir=""])
+AM_CONDITIONAL(UDEVDIR, [test "$ac_cv_udevdir" != ""])
 AC_SUBST(UDEVDIR, $ac_cv_udevdir)
 
 dnl Checks for library functions.

pktsetup/Makefile.am

@@ -2,9 +2,13 @@ sbin_PROGRAMS = pktsetup
 pktsetup_SOURCES = pktsetup.c
 EXTRA_DIST = pktsetup.rules
 
+if UDEVDIR
+
 install-data-local:
 	mkdir -p "$(DESTDIR)$(UDEVDIR)/rules.d"
 	$(INSTALL_DATA) "$(srcdir)/pktsetup.rules" "$(DESTDIR)$(UDEVDIR)/rules.d/80-pktsetup.rules"
 
 uninstall-local:
 	rm -f "$(DESTDIR)$(UDEVDIR)/rules.d/80-pktsetup.rules"
+
+endif