ping: Fix bell char ordering in -A test cases

Previously, these tests expected the bell chars to arrive
before the initial status line. This appeared to be ok because
ping(8) incorrectly mixed unbuffered and buffered writes by using
printf(3) calls for the initial status, but direct write(2) calls
for the bell chars. 141bb85798 revealed that the test's assertions
only passed because the buffered writes did not get flushed before
the direct writes in the test runs.

8bda488114 fixed ping(8) to use POSIX stdio buffered writes
in all cases and guarantee a deterministic output ordering to stdout
observers. This patch fixes the test to match the correct ordering.

Reviewed by:	des
Sponsored by:	The FreeBSD Foundation

sbin/ping/tests/test_ping.py

@@ -431,8 +431,8 @@ round-trip min/avg/max/stddev = /// ms
                 "args": "ping -A -c3 192.0.2.2",
                 "returncode": 2,
                 "stdout": """\
-\x07\x07PING 192.0.2.2 (192.0.2.2): 56 data bytes
-
+PING 192.0.2.2 (192.0.2.2): 56 data bytes
+\x07\x07
 --- 192.0.2.2 ping statistics ---
 3 packets transmitted, 0 packets received, 100.0% packet loss
 """,
@@ -463,8 +463,8 @@ round-trip min/avg/max/stddev = /// ms
                 "args": "ping -A -c3 2001:db8::2",
                 "returncode": 2,
                 "stdout": """\
-\x07\x07PING(56=40+8+8 bytes) 2001:db8::1 --> 2001:db8::2
-
+PING(56=40+8+8 bytes) 2001:db8::1 --> 2001:db8::2
+\x07\x07
 --- 2001:db8::2 ping statistics ---
 3 packets transmitted, 0 packets received, 100.0% packet loss
 """,