fix O_EXCL handling for devices

O_EXCL without O_CREAT has different semantics; it's "fail if already opened",
not "fail if already exists".  commit 71574865 broke that...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-07-30 11:50:30 +04:00
commit f8310c5920