code_relocation: fix ruff SUM401 warning

The ruff python linter produces a SIM401 warning when a dictionary is
accessed using if-statements to check for key presence. In this case, the
dict.get() method could be used instead.

For example:

    value = foo["bar"] if "bar" in foo else 0

...can be replaced with:

    value = foo.get("bar", 0)

This patch corrects the single instance of this issue in the script.

Signed-off-by: Joel Holdsworth <jholdsworth@nvidia.com>