xbps-src: trying to fix FFLAGS construction

This still isn't perfect. When the common/xbps-src/shutils/chroot.sh
function chroot_init() is called, the value for $XBPS_FFLAGS, which is
defined in common/build-profiles/bootstrap.sh, is empty.

Put the immediate value into the generated /etc/xbps/xbps-src.conf
file until someone finds out where passing the value of $XBPS_FFLAGS
throughout the scripts is missing.

common/xbps-src/shutils/chroot.sh

@@ -1,5 +1,7 @@
 # vim: set ts=4 sw=4 et:
 
+# FIXME: $XBPS_FFLAGS is not set when chroot_init() is run
+# It is set in common/build-profiles/bootstrap.sh but lost somewhere?
 chroot_init() {
     XBPSSRC_CF=$XBPS_MASTERDIR/etc/xbps/xbps-src.conf
 
@@ -15,9 +17,9 @@ _EOF
 XBPS_MASTERDIR=/
 XBPS_CFLAGS="$XBPS_CFLAGS"
 XBPS_CXXFLAGS="$XBPS_CXXFLAGS"
+XBPS_FFLAGS="-fPIC -pipe"
 XBPS_CPPFLAGS="$XBPS_CPPFLAGS"
 XBPS_LDFLAGS="$XBPS_LDFLAGS"
-XBPS_FFLAGS="$XBPS_FFLAGS"
 XBPS_HOSTDIR=/host
 _EOF