test/osd: Make error messages that occur based on configuration problems or user error more readable in ceph_test_rados_io_sequence
Move away from using ceph_abort for error messages that occur from configuration issues and user error to printing to std::error as it is not necissairy to produce a call stack and core dumps in these cases and much better to give an easily readable message to the user.
Signed-off-by: Jon Bailey <jonathan.bailey1@ibm.com>