ls-remote: set packet_trace_identity(<name>)

Set packet_trace_identity() for ls-remote. This replaces the generic
"git" identity in GIT_TRACE_PACKET=<file> traces to "ls-remote", e.g.:

    [...] packet:  upload-pack> version 2
    [...] packet:  upload-pack> agent=git/2.32.0-dev
    [...] packet:    ls-remote< version 2
    [...] packet:    ls-remote< agent=git/2.32.0-dev

Where in an "git ls-remote file://<path>" dialog ">" is the sender (or
"to the server") and "<" is the recipient (or "received by the
client").

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/ls-remote.c

@@ -84,6 +84,8 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 	dest = argv[0];
 
+	packet_trace_identity("ls-remote");
+
 	UNLEAK(sorting);
 
 	if (argc > 1) {

t/t5702-protocol-v2.sh

@@ -27,9 +27,9 @@ test_expect_success 'list refs with git:// using protocol v2' '
 		ls-remote --symref "$GIT_DAEMON_URL/parent" >actual &&
 
 	# Client requested to use protocol v2
-	grep "git> .*\\\0\\\0version=2\\\0$" log &&
+	grep "ls-remote> .*\\\0\\\0version=2\\\0$" log &&
 	# Server responded using protocol v2
-	grep "git< version 2" log &&
+	grep "ls-remote< version 2" log &&
 
 	git ls-remote --symref "$GIT_DAEMON_URL/parent" >expect &&
 	test_cmp expect actual
@@ -151,7 +151,7 @@ test_expect_success 'list refs with file:// using protocol v2' '
 		ls-remote --symref "file://$(pwd)/file_parent" >actual &&
 
 	# Server responded using protocol v2
-	grep "git< version 2" log &&
+	grep "ls-remote< version 2" log &&
 
 	git ls-remote --symref "file://$(pwd)/file_parent" >expect &&
 	test_cmp expect actual