drm/i915: make sparse happy for the new vlv mmio read function

It doesn't like that we assign 0 to a pointer, it wants the real NULL.

On closer look that initialization is actually bogus, and the compiler
can easily see that we never use it unitialized. So let's just drop
this.

Cc: Deepak S <deepak.s@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_uncore.c

@@ -479,7 +479,7 @@ gen6_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
 static u##x \
 vlv_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
 	unsigned fwengine = 0; \
-	unsigned *fwcount = 0; \
+	unsigned *fwcount; \
 	REG_READ_HEADER(x); \
 	if (FORCEWAKE_VLV_RENDER_RANGE_OFFSET(reg)) {   \
 		fwengine = FORCEWAKE_RENDER;            \