toolchain-shar-template.sh: fix installation of SDK

toolchain-shar-template.sh: fix installation of SDK

Previously, the installation of our SDK is not consistent.

For example, there's a user with user name 'test' and group name 'test', and
the user has sudo privilege. First, the user tries to install the SDK to his
own home directory /home/test, and the SDK files are installed with 'test' as
their owner. Then, the user tries to install the SDK to /opt/ directory which
is owned by root, and the SDK files are installed with 'root' as their owner.

We can see from the above example the same SDK would result in different
installation results only because the installation directories are different.

In fact, in the second use case above, the user has to use the `sudo' command
every time whenever he/she wants to perform some action with the SDK.

This patch fixes the above problems by installing the SDK with the current user
as the owner of the installed files.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>