p2p: fix reply message for deletePersistentGroup

When deletePersistentGroup fails, it will reply message
with what=DELETE_PERSISTENT_GROUP but the correct value should
be DELETE_PERSISTENT_GROUP_FAILED.

Bug: 122931321
Test: ./frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: I94c5a78012f7cf4bac7c4b99ca24ae6f5bab1579
2 files changed