Offset calculations are easy enough to get wrong. Let's add a few
variables to make moving around elf headers and data sections easier.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220330123603.107120-6-frankja@linux.ibm.com>