Fix libnl CFLAGS/LIBS inclusion

When using libnl, use the variables pkg-config provides in case there are
additional libraries or CFLAGS required to build it. Specifically if
the libnl headers are not directly in /usr/include.

daemon/Makefile.am

@@ -96,7 +96,7 @@ libvirtd_SOURCES = $(DAEMON_SOURCES)
 #-D_XOPEN_SOURCE=600 -D_XOPEN_SOURCE_EXTENDED=1 -D_POSIX_C_SOURCE=199506L
 libvirtd_CFLAGS = \
 	$(LIBXML_CFLAGS) $(GNUTLS_CFLAGS) $(SASL_CFLAGS) \
-	$(XDR_CFLAGS) $(POLKIT_CFLAGS) $(DBUS_CFLAGS) \
+	$(XDR_CFLAGS) $(POLKIT_CFLAGS) $(DBUS_CFLAGS) $(LIBNL_CFLAGS) \
 	$(WARN_CFLAGS) \
 	$(COVERAGE_CFLAGS) \
 	-DQEMUD_PID_FILE="\"$(QEMUD_PID_FILE)\"" \
@@ -111,7 +111,8 @@ libvirtd_LDADD =					\
 	$(GNUTLS_LIBS)					\
 	$(SASL_LIBS)					\
 	$(DBUS_LIBS)					\
-	$(POLKIT_LIBS)
+	$(POLKIT_LIBS)					\
+	$(LIBNL_LIBS)
 
 if WITH_DTRACE_PROBES
 libvirtd_LDADD += ../src/libvirt_probes.lo