watch_queue: Make comment about setting ->defunct more accurate

watch_queue: Make comment about setting ->defunct more accurate

BugLink: https://bugs.launchpad.net/bugs/1966056
commit 4edc0760412b0c4ecefc7e02cb855b310b122825 upstream.

watch_queue_clear() has a comment stating that setting ->defunct to true
preventing new additions as well as preventing notifications.  Whilst
the latter is true, the first bit is superfluous since at the time this
function is called, the pipe cannot be accessed to add new event
sources.

Remove the "new additions" bit from the comment.

Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>