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_arm.go b/src/pkg/syscall/syscall_linux_arm.go
index 547a4eb..f2859cf 100644
--- a/src/pkg/syscall/syscall_linux_arm.go
+++ b/src/pkg/syscall/syscall_linux_arm.go
@@ -55,7 +55,7 @@
//sys Lchown(path string, uid int, gid int) (err error) = SYS_LCHOWN32
//sys Listen(s int, n int) (err error)
//sys Lstat(path string, stat *Stat_t) (err error) = SYS_LSTAT64
-//sys Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) = SYS_SENDFILE64
+//sys sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) = SYS_SENDFILE64
//sys Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) = SYS__NEWSELECT
//sys Setfsgid(gid int) (err error) = SYS_SETFSGID32
//sys Setfsuid(uid int) (err error) = SYS_SETFSUID32
