drm/i915: Remove unused i915_gem_active_wait() in favour of _unlocked()

Since we only use the more generic unlocked variant, just rename it as
the normal i915_gem_active_wait(). The temporary cost is that we need to
always acquire the reference in a RCU safe manner, but the benefit is
that we will combine the common paths.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-5-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 884a5ae..09bb89c 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -524,7 +524,7 @@ static inline int intel_engine_idle(struct intel_engine_cs *engine,
 				    unsigned int flags)
 {
 	/* Wait upon the last request to be completed */
-	return i915_gem_active_wait_unlocked(&engine->last_request, flags);
+	return i915_gem_active_wait(&engine->last_request, flags);
 }
 
 int intel_init_render_ring_buffer(struct intel_engine_cs *engine);