lib: s390x: Handle debug prints for SIE exceptions correctly

When we leave SIE due to an exception, we'll still have guest values
in registers 0 - 13 and that's not clearly portraied in our debug
prints. So let's fix that.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20230112154548.163021-8-frankja@linux.ibm.com
Message-Id: <20230112154548.163021-8-frankja@linux.ibm.com>