code review 162390043: os: fix build

os: fix build

[rsc, 2014-10-28 19:34:49]

Hello crawshaw (cc: golang-codereviews@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2014-10-28 19:34:55]

*** Submitted as https://code.google.com/p/go/source/detail?r=154674021c55 ***

os: fix build

TBR=crawshaw
CC=golang-codereviews
https://codereview.appspot.com/162390043

[crawshaw, 2014-10-28 19:42:25]

LGTM for fixing the build, but I think lseek returns -1 on error. Is letting
that propagate what you want?

[rsc, 2014-10-28 19:49:14]

seek returns an absolute offset, not a count, so i don't care much.
it's not going to get incorrect added to a running total.