greybus: manifest: simplify descriptor address calculation

This patch doesn't change any functionality. It just improves the
readability of the code.
Current code to get 'descriptors' pointer looks as if we are forcing the
pointer type change. To simplify the address calculations, use
'descriptors' member directly from greybus_manifest structure.
Signed-off-by: Sachin Pandhare <sachin.pandhare@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/manifest.c

@@ -475,7 +475,7 @@ bool gb_manifest_parse(struct gb_interface *intf, void *data, size_t size)
 	}
 
 	/* OK, find all the descriptors */
-	desc = (struct greybus_descriptor *)(header + 1);
+	desc = manifest->descriptors;
 	size -= sizeof(*header);
 	while (size) {
 		int desc_size;