Remove unused variables/labels to eliminate compile warnings.

Test: built and run on Marlin and testing with various USB peripherals.
Bug:70180519
Merged-Id: I68d7d33ffff8983117508e02a76d62c71d708c76
(cherry picked from commit 96c4d3035a94dbdc94f156989e22cddd495eeb51)

Change-Id: If2a11bb5e649472d8bc25b5804715d6da48e5330
1 file changed