drm/i915: don't mix bitwise and logical operations for has_snoop

Also make the code more readable.
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463148278-23193-2-git-send-email-jani.nikula@intel.com

drivers/gpu/drm/i915/i915_dma.c

@@ -954,9 +954,11 @@ static void intel_device_info_runtime_init(struct drm_device *dev)
 	else if (INTEL_INFO(dev)->gen >= 9)
 		gen9_sseu_info_init(dev);
 
-	/* Snooping is broken on BXT A stepping. */
 	info->has_snoop = !info->has_llc;
-	info->has_snoop &= !IS_BXT_REVID(dev, 0, BXT_REVID_A1);
+
+	/* Snooping is broken on BXT A stepping. */
+	if (IS_BXT_REVID(dev, 0, BXT_REVID_A1))
+		info->has_snoop = false;
 
 	DRM_DEBUG_DRIVER("slice total: %u\n", info->slice_total);
 	DRM_DEBUG_DRIVER("subslice total: %u\n", info->subslice_total);