reflect: remove extra word in comment

Change-Id: I06881fc447a5fae0067557c317f69a0427bed337
Reviewed-on: https://go-review.googlesource.com/2760
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/reflect/value.go

@@ -732,7 +732,7 @@ func (v Value) Field(i int) Value {
 	// Either flagIndir is set and v.ptr points at struct,
 	// or flagIndir is not set and v.ptr is the actual struct data.
 	// In the former case, we want v.ptr + offset.
-	// In the latter case, we must be have field.offset = 0,
+	// In the latter case, we must have field.offset = 0,
 	// so v.ptr + field.offset is still okay.
 	ptr := unsafe.Pointer(uintptr(v.ptr) + field.offset)
 	return Value{typ, ptr, fl}