Make fingerprint handling compatible with LTO

Tell the compiler that the fingerprint variable is modified unpredictably.

* lib/fingerprint.h (fingerprint): Remove const.
* lib/fingerprint.c (fingerprint): Likewise.
* src/pdumper.c (Fdump_emacs_portable): Cast fingerprint variable.
(pdumper_load): Likewise.
* lib-src/make-fingerprint.c (main): Likewise.
1 job for master in 90 minutes (queued for 3 seconds)
Status Job ID Name Coverage
failed #2465


Name Stage Failure
test-all Test The script exceeded the maximum execution time set for the job
make -C test check-expensive
make[1]: Entering directory '/builds/emacs/emacs/test'
rm -f ./*.tmp
make[2]: Entering directory '/builds/emacs/emacs/test'
make[3]: Entering directory '/builds/emacs/emacs/test'
ELC lisp/net/tramp-tests.elc
GEN lisp/net/tramp-tests.log
Pulling docker image gitlab/gitlab-runner-helper:x86_64-f100a208 ...
ERROR: Job failed: execution took longer than 1h30m0s seconds