Some libc's like musl libc don't provide execinfo.h since it's not part of
POSIX. In order to fix compilation on musl, only include execinfo.h if
available (HAVE_BACKTRACE_SUPPORT)
This was discovered with c104c16073 ("Kunit to check the longest symbol
length") which starts to include linux/kallsyms.h with Alpine Linux'
configs.
Link: https://lkml.kernel.org/r/20250622014608.448718-1-fossdd@pwned.life
Fixes: c104c16073 ("Kunit to check the longest symbol length")
Signed-off-by: Achill Gilgenast <fossdd@pwned.life>
Cc: Luis Henriques <luis@igalia.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
a95743b530