hidpp20: fix NULL-pointer dereference warning

rc may be a negative errno or a positive hidpp error code. If the latter we
used to continue with a NULL macro pointer, eventually crashing.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/hidpp20.c

@@ -1552,7 +1552,7 @@ hidpp20_onboard_profiles_parse_macro(struct hidpp20_device *device,
 	int rc;
 
 	rc = hidpp20_onboard_profiles_read_macro(device, page, offset, &macro);
-	if (rc < 0)
+	if (rc)
 		return rc;
 
 	count = rc;