os: increase default write size for TestClosedPipeRaceWrite

The original value of 65537 consistently caused the test to fail on
Solaris. The new value of 131073 consistently lets the test pass.

Change-Id: If1a76ab89aa8f661ea049113addd04b23a116534
Reviewed-on: https://go-review.googlesource.com/c/152164
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/os/pipe_test.go

@@ -131,7 +131,7 @@ func testClosedPipeRace(t *testing.T, read bool) {
 	if !read {
 		// Get the amount we have to write to overload a pipe
 		// with no reader.
-		limit = 65537
+		limit = 131073
 		if b, err := ioutil.ReadFile("/proc/sys/fs/pipe-max-size"); err == nil {
 			if i, err := strconv.Atoi(strings.TrimSpace(string(b))); err == nil {
 				limit = i + 1