meson: fix a build error for libbpf at release build

[sirlucjan]

Fix error:

INFO: autodetecting backend as ninja
INFO: calculating backend command to run: /usr/bin/ninja -C /home/lucjan/Pobrane/scx-scheds-git/src/scx/build ninja: Entering directory `/home/lucjan/Pobrane/scx-scheds-git/src/scx/build' [2/31] Generating bpftool_target with a custom command FAILED: bpftool_dummy.c.__PHONY__
/bin/bash /home/lucjan/Pobrane/scx-scheds-git/src/scx/meson-scripts/build_bpftool /usr/bin/jq /usr/bin/make /home/lucjan/Pobrane/scx-scheds-git/src/scx/build/bpftool/src 4 libbpf.c: In function ‘bpf_object__gen_loader’:
libbpf.c: In function ‘bpf_object__gen_loader’:
libbpf.c:8994:28: error: ‘calloc’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Werror=calloc-transposed-args]
 8994 |         gen = calloc(sizeof(*gen), 1);
      |                            ^
libbpf.c:8994:28: error: ‘calloc’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Werror=calloc-transposed-args]
 8994 |         gen = calloc(sizeof(*gen), 1);
      |                            ^
libbpf.c:8994:28: note: earlier argument should specify number of elements, later size of each element
libbpf.c:8994:28: note: earlier argument should specify number of elements, later size of each element
At top level:
cc1: note: unrecognized command-line option ‘-Wno-unknown-warning-option’ may have been intended to silence earlier diagnostics
cc1: all warnings being treated as errors
make[1]: *** [Makefile:134: /home/lucjan/Pobrane/scx-scheds-git/src/scx/build/bpftool/src/bootstrap/libbpf/staticobjs/libbpf.o] Error 1
make: *** [Makefile:52: /home/lucjan/Pobrane/scx-scheds-git/src/scx/build/bpftool/src/bootstrap/libbpf/libbpf.a] Error 2
make: *** Waiting for unfinished jobs....
At top level:
cc1: note: unrecognized command-line option ‘-Wno-unknown-warning-option’ may have been intended to silence earlier diagnostics
cc1: all warnings being treated as errors
make[1]: *** [Makefile:134: /home/lucjan/Pobrane/scx-scheds-git/src/scx/build/bpftool/src/libbpf/staticobjs/libbpf.o] Error 1
make: *** [Makefile:44: /home/lucjan/Pobrane/scx-scheds-git/src/scx/build/bpftool/src/libbpf/libbpf.a] Error 2
ninja: build stopped: subcommand failed.

[arighi]

LGTM