cbfstool/ifwitool: Remove unnecessary assignment

Fix the warning below.

```
util/cbfstool/ifwitool.c:551:2: warning: Value stored to 'offset' is never read
        offset = read_member(data, offset, sizeof(h->fit_tool_version),
        ^        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

Found-by: scan-build from clang 3.8.1
Change-Id: I6c322a335a371a20561b32e04e7dcc7310dab607
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-on: https://review.coreboot.org/18667
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>

0 files changed, 0 insertions, 0 deletions