elfutils: Fix build with gcc trunk

elfutils: Fix build with gcc trunk

Fixes a build issue seen with latest gcc trunk.

Fixes
| ../../elfutils-0.189/tests/elfstrmerge.c: In function 'main':
| ../../elfutils-0.189/tests/elfstrmerge.c:450:32: error: 'calloc' sizes specified with 'sizeof' in the earlier argument and not in the later argument [-Werror=calloc-transposed-args]
|   450 |   newscnbufs = calloc (sizeof (void *), newshnums);
|       |                                ^~~~
| ../../elfutils-0.189/tests/elfstrmerge.c:450:32: note: earlier argument should specify number of elements, later size of each element
| cc1: all warnings being treated as errors

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>