opkg: Don't call sync() when installing into an offline root
Even when installing onto a live target system, calling sync() during
package installation is of somewhat questionable benefit. But calling
it on the build host during rootfs construction is certainly useless and
can cause I/O to stall for several seconds on even a moderately sized
host which is clearly not desirable.
(From a patch originally by Mike Crowe.)
Signed-off-by: Phil Blundell <philb@gnu.org> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
