xhci: dbc: Drop duplicate checks for dma_free_coherent()

dma_free_coherent() is NULL-aware, not necessary to check for
the parameter twice. Drop duplicate conditionals in the caller.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231201150647.1307406-2-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>