[PATCH] reiserfs: reiserfs_file_write() will lose error code when a 0-length write occurs w/ O_SYNC

When an error occurs in reiserfs_file_write before any data is written, and
O_SYNC is set, the return code of generic_osync_write will overwrite the
error code, losing it.

This patch ensures that generic_osync_inode() doesn't run under an error
condition, losing the error.  This duplicates the logic from
generic_file_buffered_write().

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Alexander Zarochentsev <zam@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>