ARM posix_fadvise calls __posix_fadvise64_l64, to which
posix_fadvise64 is a strong alias, but posix_fadvise is a POSIX
function and posix_fadvise64 isn't. This patch changes it into a weak
alias.
Tested for ARM that this fixes the corresponding linknamespace test
failures.
[BZ #17793]
* sysdeps/unix/sysv/linux/arm/posix_fadvise64.c (posix_fadvise64):
Define as weak alias not strong alias.