Races galore... General rule: as soon as it's in descriptor table,
it's over; another thread might have started IO on it/dup2() it
elsewhere/dup2() something *over* it/etc. fd_install() is the very
last step one should take - it's a point of no return.
Besides, the damn thing leaked on failure exits...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tony Luck <tony.luck@intel.com>
f8e811b989