NFS41: pop some layoutget errors to application

For ERESTARTSYS/EIO/EROFS/ENOSPC/E2BIG in layoutget, we
should just bail out instead of hiding the error and
retrying inband IO.

Change all the call sites to pop the error all the way up.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 0a5e33f..0bb5801 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -115,7 +115,7 @@
 	pgm = &pgio.pg_mirrors[0];
 	NFS_I(inode)->read_io += pgm->pg_bytes_written;
 
-	return 0;
+	return pgio.pg_error < 0 ? pgio.pg_error : 0;
 }
 
 static void nfs_readpage_release(struct nfs_page *req)