Don't call unsafe functions from SIGSEGV/SIGBUS signal handler.

GCC10 -fanalyzer notices that we try to call functions that are not
signal safe from our fatal signal handler:

bzip2.c: In function ‘mySIGSEGVorSIGBUScatcher’:
bzip2.c:819:7: warning: call to ‘fprintf’ from within signal handler
               [CWE-479] [-Wanalyzer-unsafe-call-within-signal-handler]

It also notices we then call showFileNames and cleanupAndFail which
also call possibly not signal safe functions.

Just write out the error message directly to STDERR and exit without
trying to clean up any files.
1 file changed