btrfs: use E2BIG instead of EIO if compression does not help

Return codes got updated in 60e1975acb48fc3d74a3422b21dde74c977ac3d5
(btrfs: return errno instead of -1 from compression)
lzo wrapper returns E2BIG in this case, do the same for zlib.

Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 4f19631..b67d8fc 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -136,7 +136,7 @@
 		if (workspace->def_strm.total_in > 8192 &&
 		    workspace->def_strm.total_in <
 		    workspace->def_strm.total_out) {
-			ret = -EIO;
+			ret = -E2BIG;
 			goto out;
 		}
 		/* we need another page for writing out.  Test this