Don't call `getArguments` unnecessarily

Remove a second call to `getArguments` by reusing the value returned
from the first call.

That call was added in Ie6dd9b13711bae65f6fd6d1a5286307cd0cf2ad3
which neglected to perform this simplification.

Change-Id: I2186db1fa3158886dc785557e977e7a25bfe4c72