dasdfmt: Improve error message construction
dasdfmt: Improve error message construction

In check_track_format() the base error message is the same for all cases
but has different additional content depending on which mode dasdfmt is
running.

Currently the message is compiled by using different outputs. To make it
a little bit cleaner and for a better error message handling, construct
the message string completely before passing it to the error() function
for output.

Reviewed-by: Stefan Haberland <dec981e3bbb165d021029c42291faf06f59827c1@linux.ibm.com>
Signed-off-by: Jan Höppner <96138615ab4af0813785fa10d283f3d37eca3b78@linux.ibm.com>

ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools