doc txt & -h consistency: use "git foo" form, not "git-foo"

Use the "git cmd" form instead of "git-cmd" for both "git
receive-pack" and "git credential-cache--daemon".

For "git-receive-pack" we do have a binary with that name, even when
installed with SKIP_DASHED_BUILT_INS=YesPlease, but for the purposes
of the SYNOPSIS let's use the "git cmd" form like everywhere else. It
can be invoked like that (and our tests do so), the parts of our
documentation that explain when you need to use the dashed form do so,
and use it.

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

Documentation/git-receive-pack.txt

@@ -9,7 +9,7 @@ git-receive-pack - Receive what is pushed into the repository
 SYNOPSIS
 --------
 [verse]
-'git-receive-pack' <git-dir>
+'git receive-pack' <git-dir>
 
 DESCRIPTION
 -----------

builtin/credential-cache--daemon.c

@@ -267,7 +267,7 @@ int cmd_credential_cache_daemon(int argc, const char **argv, const char *prefix)
 	const char *socket_path;
 	int ignore_sighup = 0;
 	static const char *usage[] = {
-		"git-credential-cache--daemon [--debug] <socket-path>",
+		"git credential-cache--daemon [--debug] <socket-path>",
 		NULL
 	};
 	int debug = 0;
@@ -305,7 +305,7 @@ int cmd_credential_cache_daemon(int argc, const char **argv, const char *prefix)
 int cmd_credential_cache_daemon(int argc, const char **argv, const char *prefix)
 {
 	const char * const usage[] = {
-		"git credential-cache--daemon [options] <action>",
+		"git credential-cache--daemon [--debug] <socket-path>",
 		"",
 		"credential-cache--daemon is disabled in this build of Git",
 		NULL