selftests: rtnetlink: update netdevsim ipsec output format

After the netdevsim update to use human-readable IP address formats for
IPsec, we can now use the source and destination IPs directly in testing.
Here is the result:
  # ./rtnetlink.sh -t kci_test_ipsec_offload
  PASS: ipsec_offload

Signed-off-by: Hangbin Liu <[email protected]>
Acked-by: Stanislav Fomichev <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: liuhangbin

tools/testing/selftests/net/rtnetlink.sh

@@ -809,10 +809,10 @@ kci_test_ipsec_offload()
 	# does driver have correct offload info
 	run_cmd diff $sysfsf - << EOF
 SA count=2 tx=3
-sa[0] tx ipaddr=0x00000000 00000000 00000000 00000000
+sa[0] tx ipaddr=$dstip
 sa[0]    spi=0x00000009 proto=0x32 salt=0x61626364 crypt=1
 sa[0]    key=0x34333231 38373635 32313039 36353433
-sa[1] rx ipaddr=0x00000000 00000000 00000000 037ba8c0
+sa[1] rx ipaddr=$srcip
 sa[1]    spi=0x00000009 proto=0x32 salt=0x61626364 crypt=1
 sa[1]    key=0x34333231 38373635 32313039 36353433
 EOF