build: fix detection of netcf linked with libnl1

Commit 9298bfbcb introduced code to detect if netcf is linked with
libnl1, and to prefer libnl1 over libnl3 when this is the case.
This behaviour can be disabled by setting LIBNL_CFLAGS to any value,
including the empty string.
However, configure.ac sets LIBNL_CFLAGS to "" before attempting
libnl detection, so the libnl1 detection code is always disabled.
This caused issues on my f17 system where netcf is linked with libnl1
but libvirt got built with libnl3.

This commit removes the setting of the LIBNL_* variables to "" as
this does not appear to be needed. After this change, libnl1 is
used when building libvirt on my f17 system.

diff --git a/configure.ac b/configure.ac
index 3e9073d283a84d3680c654add9038fd5af3cb360..38d94d40a84274e6e530951e5ee7ad356358592c 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -2925,10 +2925,6 @@ AM_CONDITIONAL([WITH_VIRTUALPORT], [test "$with_virtualport" = "yes"])
 
 dnl netlink library
 
-LIBNL_ROUTE3_CFLAGS=""
-LIBNL_ROUTE3_LIBS=""
-LIBNL_CFLAGS=""
-LIBNL_LIBS=""
 have_libnl=no
 
 if test "$with_linux" = "yes"; then