qt4-tools-native: set LFLAGS to pick up zlib from staging

Original Author: Jeremy Lainé <jeremy.laine@m4x.org>
Upstream-Status: Pending

Index: qt-everywhere-opensource-src-4.8.0/configure
===================================================================
--- qt-everywhere-opensource-src-4.8.0.orig/configure
+++ qt-everywhere-opensource-src-4.8.0/configure
@@ -611,7 +611,7 @@ fi
 # initalize variables
 #-------------------------------------------------------------------------------
 
-SYSTEM_VARIABLES="RANLIB STRIP OBJDUMP LD CC CXX CFLAGS CXXFLAGS LDFLAGS"
+SYSTEM_VARIABLES="RANLIB STRIP OBJDUMP LD CC CXX CFLAGS CXXFLAGS LDFLAGS LFLAGS"
 for varname in $SYSTEM_VARIABLES; do
     qmakevarname="${varname}"
     # use LDFLAGS for autoconf compat, but qmake uses QMAKE_LFLAGS