display: change Skipf to Errorf

Inconsistencies in CLDR are here to stay (see comments in
http://unicode.org/cldr/trac/ticket/8051), so we might as well make
this official.

Change-Id: I2eea4cbd60e9037e786f3ecb86cbbf904bb8636c
Reviewed-on: https://go-review.googlesource.com/12904
Reviewed-by: Nigel Tao <nigeltao@golang.org>
1 file changed