wifi: iwlwifi: Fix the duplicate dump name

Driver is using the dump name generated first time in all
generated dump in case of NMI.
The validity of dump name should be with each dump created
and need to reset after each use.

Fixes: 834f920e

 ("wifi: iwlwifi: yoyo: Add driver defined dump file name")
Signed-off-by: Mukesh Sisodiya <mukesh.sisodiya@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230413213309.6c987f820557.I924f2eae1eef2fe82c7a23be566551653d46f729@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>