More correct H2O update mode handling...

The H2O, while having a Carta screen, doesn't actually handle REAGL
properly, thanks to some strange decision on kobo's part.

I've been confusing everyone from the start because I was convinced
it would handle REAGL, having a Carta screen, and having been released
after the Aura, but, nope.
Besides sniffing the ioctl with strace, that's also easily confirmed
by checking Nickel's settings: on the H2O, we only have the classic page
count refresh setting available, and not the extended one available on
the Aura.

TL;DR: Make it behave like other non-RAGL Kobo devices, instead of brokenly
treating it like a special snowflake ;).

ffi/framebuffer_mxcfb.lua

@@ -368,8 +368,8 @@ function framebuffer:init()
             self.wait_for_marker_fast = true
         elseif self.device.model == "Kobo_dahlia" then
             self.wait_for_marker_full = true
-            self.wait_for_marker_partial = true
-            self.wait_for_marker_fast = true
+            self.wait_for_marker_partial = false
+            self.wait_for_marker_fast = false
         elseif self.device.model == "Kobo_pixie" then
             self.wait_for_marker_full = true
             self.wait_for_marker_partial = false