Revert "[PATCH] generic_file_buffered_write(): handle zero-length iovec segments"

Revert "[PATCH] generic_file_buffered_write(): handle zero-length iovec segments"

This reverts commit fdaa8d4e266e02d30fb9892c95209d30362a01a6, which was
a bugfix against d74ba2480d1259d925654610269da65b4c3c16a7 ("[PATCH]
generic_file_buffered_write(): deadlock on vectored write"), which we
also revert.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>