Blindly setting FD_CLOEXEC without a read-modify-write will
inadvertently clear any other intentionally-set bits, such as a
proposed new bit for designating a fd that must behave in 32-bit mode.
Use our wrapper function instead of an incorrect hand-rolled version.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200420175309.75894-2-eblake@redhat.com>
Reviewed-by: Colin Xu <colin.xu@intel.com>