linux-dmabuf: clarify format event description

clearly state the request name in format event to avoid abmiguous
interpretation between 'zwp_linux_buffer_params_v1::create' and
'zwp_linux_dmabuf_v1::create_params' requests.

v2: grammar fixup (Yong Bakos)

Signed-off-by: Varad Gautam <varad.gautam@collabora.com>
Suggested-by: Yong Bakos <ybakos@humanoriented.com>
Reviewed-by: Yong Bakos <ybakos@humanoriented.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>

unstable/linux-dmabuf/linux-dmabuf-unstable-v1.xml

@@ -98,7 +98,8 @@
         binds to this interface. A roundtrip after binding guarantees
         that the client has received all supported formats.
 
-        For the definition of the format codes, see create request.
+        For the definition of the format codes, see the
+        zwp_linux_buffer_params_v1::create request.
 
         XXX: Can a compositor ever enumerate them?
       </description>