syscalls: annotate Sendfile() for race detector
Fixes #4306.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/6816054
diff --git a/src/pkg/syscall/syscall_linux_amd64.go b/src/pkg/syscall/syscall_linux_amd64.go
index 54d8dbe..b0d236c 100644
--- a/src/pkg/syscall/syscall_linux_amd64.go
+++ b/src/pkg/syscall/syscall_linux_amd64.go
@@ -23,7 +23,7 @@
//sys Pwrite(fd int, p []byte, offset int64) (n int, err error) = SYS_PWRITE64
//sys Seek(fd int, offset int64, whence int) (off int64, err error) = SYS_LSEEK
//sys Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error)
-//sys Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
+//sys sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
//sys Setfsgid(gid int) (err error)
//sys Setfsuid(uid int) (err error)
//sysnb Setgid(gid int) (err error)
