We are going to rename and modify pump_transfers(). Prepare for it by
removing the string "pump_transfers:" from error and warning prints.

While at it make these user-visible strings single line in sources as it
helps source grepping from error reports.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>