drm/i915/guc: Use correct name for last CT fence

While we have function that returns "next fence" that can be used
by new CT request, we internally store value of the last used fence.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200111231114.59208-5-michal.wajdeczko@intel.com

drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c

@@ -290,7 +290,7 @@ void intel_guc_ct_disable(struct intel_guc_ct *ct)
 static u32 ct_get_next_fence(struct intel_guc_ct *ct)
 {
 	/* For now it's trivial */
-	return ++ct->requests.next_fence;
+	return ++ct->requests.last_fence;
 }
 
 /**

drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h

@@ -49,7 +49,7 @@ struct intel_guc_ct {
 	struct intel_guc_ct_buffer ctbs[2];
 
 	struct {
-		u32 next_fence; /* fence to be used with next request to send */
+		u32 last_fence; /* last fence used to send request */
 
 		spinlock_t lock; /* protects pending requests list */
 		struct list_head pending; /* requests waiting for response */