scripts/functions: use patch -i instead of IO redirection

This makes the patch name show up on the command line
logged by CT_DoExecLog so it's easier to see
what is going on. The -i for patch is specified
by Posix and supported by GNU patch and busybox patch.

Signed-off-by: Johannes Stezenbach <js@sig21.net>
[yann.morin.1998@free.fr: remove now-useless debug message]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <20121030103620.GB8303@sig21.net>
Patchwork-Id: 195418

 # Compute s390-specific values

 CT_DoArchTupleValues() {

     # That's the only thing to override

     if [ "${CT_ARCH_64}" = "y" ]; then

         CT_TARGET_ARCH="s390x"

     fi

 }