thunderbolt: No need to loop over all retimers if access fails

When we read the NVM authentication status or unsetting the inbound SBTX
there is no point to continue the loop after first access to a retimer
fails because there won't be any more retimers after this anyway so bail
out from the loops early.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>