drm/i915: Rename 'reg' to 'clk_reg' to unconfuse it from the other 'reg'

On VLV/CHV the rc6 residency calculations read a second register to
determine the actual units used for the residency value. The variable
name 'reg' where that register value is stored shadows the function
argument 'reg'. That can easily leave the reader utterly confused, so
rename the internal variable to 'clk_reg'.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Deepak S<deepak.s@intel.com>
[danvet: Spellfix in commit message.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_sysfs.c

@@ -49,14 +49,14 @@ static u32 calc_residency(struct drm_device *dev, const u32 reg)
 
 	/* On VLV and CHV, residency time is in CZ units rather than 1.28us */
 	if (IS_VALLEYVIEW(dev)) {
-		u32 reg, czcount_30ns;
+		u32 clk_reg, czcount_30ns;
 
 		if (IS_CHERRYVIEW(dev))
-			reg = CHV_CLK_CTL1;
+			clk_reg = CHV_CLK_CTL1;
 		else
-			reg = VLV_CLK_CTL2;
+			clk_reg = VLV_CLK_CTL2;
 
-		czcount_30ns = I915_READ(reg) >> CLK_CTL2_CZCOUNT_30NS_SHIFT;
+		czcount_30ns = I915_READ(clk_reg) >> CLK_CTL2_CZCOUNT_30NS_SHIFT;
 
 		if (!czcount_30ns) {
 			WARN(!czcount_30ns, "bogus CZ count value");