Sanitize %__foo_sign_cmd macros

These have been in this bizarre double-command format for passing
to execve(), but there's really no point. Just make it a regular
command and pass the same argument as the pathname and argv[0].
No functional changes.

macros.in

@@ -619,7 +619,7 @@ Supplements:   (%{name} = %{version}-%{release} and langpacks-%{1})\
 #
 %__gpg			@__GPG@
 %__gpg_sign_cmd			%{shescape:%{__gpg}} \
-	gpg --no-verbose --no-armor --no-secmem-warning \
+	--no-verbose --no-armor --no-secmem-warning \
 	%{?_gpg_digest_algo:--digest-algo=%{_gpg_digest_algo}} \
 	%{?_gpg_sign_cmd_extra_args} \
 	%{?_openpgp_sign_id:-u %{shescape:%{_openpgp_sign_id}}} \
@@ -628,7 +628,7 @@ Supplements:   (%{name} = %{version}-%{release} and langpacks-%{1})\
 
 %__sq @__SQ@
 %__sq_sign_cmd		%{shescape:%{__sq}} \
-	%{__sq} sign \
+	sign \
         %{?_openpgp_sign_id:--signer-key %{_openpgp_sign_id}} \
 	%{?_sq_sign_cmd_extra_args} \
         --detached --output %{shescape:%{?__signature_filename}} \

sign/rpmgensig.cc

@@ -251,7 +251,7 @@ static int runGPG(sigTarget sigt, const char *sigfile)
 	dup2(pipefd[0], STDIN_FILENO);
 	close(pipefd[1]);
 
-	rc = execve(argv[0], argv+1, environ);
+	rc = execve(argv[0], argv, environ);
 
 	rpmlog(RPMLOG_ERR, _("Could not exec %s: %s\n"), argv[0],
 		strerror(errno));