Fix configure script for LTTng 2.x

# For 'ust' backend, test if ust headers are present

if test "$trace_backend" = "ust"; then

  cat > $TMPC << EOF

#include <ust/tracepoint.h>

#include <ust/marker.h>

#include <lttng/tracepoint.h>

int main(void) { return 0; }

EOF

  if compile_prog "" "" ; then

    LIBS="-lust -lurcu-bp $LIBS"

    libs_qga="-lust -lurcu-bp $libs_qga"

    if $pkg_config lttng-ust --exists; then

      lttng_ust_libs=`$pkg_config --libs lttng-ust`

    else

    error_exit "Trace backend 'ust' missing libust header files"

      lttng_ust_libs="-llttng-ust"

    fi

    if $pkg_config liburcu-bp --exists; then

      urcu_bp_libs=`$pkg_config --libs liburcu-bp`

    else

      urcu_bp_libs="-lurcu-bp"

    fi

    LIBS="$lttng_ust_libs $urcu_bp_libs $LIBS"

    libs_qga="$lttng_ust_libs $urcu_bp_libs $libs_qga"

  else

    error_exit "Trace backend 'ust' missing lttng-ust header files"

  fi

fi