fmt: hold on to all free buffers, regardless of size

This code made sense before fmt switched to using sync.Pool, but a
sync.Pool clears all items on GC, so not reusing something based on
size is just a waste of memory.

Change-Id: I201312b0ee6c572ff3c0ffaf71e42623a160d23f
Reviewed-on: https://go-review.googlesource.com/21480Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/fmt/print.go

@@ -132,10 +132,6 @@ func newPrinter() *pp {
 
 // free saves used pp structs in ppFree; avoids an allocation per invocation.
 func (p *pp) free() {
-	// Don't hold on to pp structs with large buffers.
-	if cap(p.buf) > 1024 {
-		return
-	}
 	p.buf = p.buf[:0]
 	p.arg = nil
 	p.value = reflect.Value{}