usb: host: xhci: use snprintf() in xhci_decode_trb()

usb: host: xhci: use snprintf() in xhci_decode_trb()

Commit cbf286e8ef83 ("xhci: fix unsafe memory usage in xhci tracing")
apparently missed one sprintf() call in xhci_decode_trb() -- replace
it with the snprintf() call as well...

Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.

Fixes: cbf286e8ef83 ("xhci: fix unsafe memory usage in xhci tracing")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220630124645.1805902-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>