zdev: fix copying of modified flag
zdev: fix copying of modified flag

The modified flag was actually never copied during merge of setting lists.
Copy the modified flag if requested.

Found using Cppcheck:
[zdev/src/setting.c:553]: (warning) Redundant assignment of 'n->modified' to itself.

Cc: Peter Oberparleiter <db44112e0f7c7459f7ecb043f101f88a2e807d9f@de.ibm.com>
Signed-off-by: Jens Remus <9647a37a176c11c7fb6887065f43509d6f3a5d2d@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <e296756d5edaffcdbc7b9904859492ff25d3fce5@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