package/ola: fix autoreconf issue for host-ola

CXX variable is overwritten with an empy value when
host-autoconf-archive package has been installed before
host-ola.

config.log:
configure:19965:  -o conftest -O2 [snip -I and -L] conftest.cpp  -ldl

Fixes:
http://autobuild.buildroot.net/results/8fa/8fa0a64422a96023a926412a033d9a4f01af5a71/build-end.log

Signed-off-by: Romain Naour <romain.naour@openwide.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ola/0002-autotools-don-t-overwrite-CC-and-CXX-with-ACX_PTHREA.patch

@@ -0,0 +1,51 @@
+From 991eef9f84a5ef58eaab8ea0a85f3b4bce7b00a3 Mon Sep 17 00:00:00 2001
+From: Romain Naour <romain.naour@openwide.fr>
+Date: Sat, 2 May 2015 01:50:14 +0200
+Subject: [PATCH] autotools: don't overwrite CC and CXX with ACX_PTHREAD
+ success
+
+If ACX_PTHREAD sucess, CC and CXX value are overwriten respectively
+to PTHREAD_CC and PTHREAD_CXX. But ACX_PTHREAD has been hacked to
+set PTHREAD_CXX variable for the C++ compiler and configure.ac has
+been modified accordingly.
+
+If ax_pthread.m4 wich provide standard AX_PTHREAD macro (and it's
+alias ACX_PTHREAD and AX_PTHREAD), is installed on the system by
+autoconf-archive package, then ax_pthread.m4 is used during
+autoreconf instread of acx_pthread.m4 bundled with ola.
+
+AX_PTHREAD macro from ax_pthread.m4 check only the thread support
+with the C compiler. As a result, the C++ compiler variable
+PTHREAD_CXX is not initialized, so CXX become empy and the build
+fail during resolv.h check.
+
+configure:19945: checking for 2-arg pthread_setname_np
+configure:19965:  -o conftest -O2 [snip -I and -L] conftest.cpp  -ldl  >&5
+./configure: line 2037: -o: command not found
+
+In the Buildroot use case, it's safe to remove CC and CXX overwrite
+since only gcc/g++ compiler are used.
+
+Signed-off-by: Romain Naour <romain.naour@openwide.fr>
+---
+ configure.ac | 4 +---
+ 1 file changed, 1 insertion(+), 3 deletions(-)
+
+diff --git a/configure.ac b/configure.ac
+index b1946b6..ef85af5 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -303,9 +303,7 @@ AM_CONDITIONAL([HAVE_NCURSES], [test "x$have_ncurses" = xyes])
+ ACX_PTHREAD([
+              LIBS="$PTHREAD_LIBS $LIBS"
+              CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+-             CXXFLAGS="$CXXFLAGS $PTHREAD_CXXFLAGS"
+-             CC="$PTHREAD_CC"
+-             CXX="$PTHREAD_CXX"],
++             CXXFLAGS="$CXXFLAGS $PTHREAD_CXXFLAGS"],
+             [AC_MSG_ERROR([Missing pthread, please install it])])
+ 
+ # pthread_setname_np can take either 1 or 2 arguments.
+-- 
+1.9.3
+