This function used the request object after decrementing its reference count
and releasing the lock.  This could in theory lead to all sorts of problems.

Fix and simplify at the same time.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>