docs: don't install corresponding man page if guest agent is disabled

No sense outputting the qemu-ga and qemu-ga-ref man pages when the guest
agent binary itself is disabled. This mirrors behaviour from before the
meson switch.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Message-Id: <20210128145801.14384-1-s.reiter@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

docs/meson.build

@@ -46,9 +46,11 @@ if build_docs
                           meson.source_root() / 'docs/sphinx/qmp_lexer.py',
                           qapi_gen_depends ]
 
+  have_ga = have_tools and config_host.has_key('CONFIG_GUEST_AGENT')
+
   man_pages = {
-        'qemu-ga.8': (have_tools ? 'man8' : ''),
-        'qemu-ga-ref.7': 'man7',
+        'qemu-ga.8': (have_ga ? 'man8' : ''),
+        'qemu-ga-ref.7': (have_ga ? 'man7' : ''),
         'qemu-qmp-ref.7': 'man7',
         'qemu-storage-daemon-qmp-ref.7': (have_tools ? 'man7' : ''),
         'qemu-img.1': (have_tools ? 'man1' : ''),