drm/nouveau: use drm_debug_enabled() to check for debug categories

Allow better abstraction of the drm_debug global variable in the
future. No functional changes.

v2: move unlikely() to drm_debug_enabled()

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: nouveau@lists.freedesktop.org
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Sean Paul <sean@poorly.run>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/34a1e7db6eab6467c6607d9a57581d1de75d87da.1572258936.git.jani.nikula@intel.com

drivers/gpu/drm/nouveau/dispnv50/disp.h

@@ -78,14 +78,14 @@ void evo_kick(u32 *, struct nv50_dmac *);
 
 #define evo_mthd(p, m, s) do {						\
 	const u32 _m = (m), _s = (s);					\
-	if (drm_debug & DRM_UT_KMS)					\
+	if (drm_debug_enabled(DRM_UT_KMS))				\
 		pr_err("%04x %d %s\n", _m, _s, __func__);		\
 	*((p)++) = ((_s << 18) | _m);					\
 } while(0)
 
 #define evo_data(p, d) do {						\
 	const u32 _d = (d);						\
-	if (drm_debug & DRM_UT_KMS)					\
+	if (drm_debug_enabled(DRM_UT_KMS))				\
 		pr_err("\t%08x\n", _d);					\
 	*((p)++) = _d;							\
 } while(0)

drivers/gpu/drm/nouveau/nouveau_drv.h

@@ -248,11 +248,11 @@ void nouveau_drm_device_remove(struct drm_device *dev);
 #define NV_INFO(drm,f,a...) NV_PRINTK(info, &(drm)->client, f, ##a)
 
 #define NV_DEBUG(drm,f,a...) do {                                              \
-	if (unlikely(drm_debug & DRM_UT_DRIVER))                               \
+	if (drm_debug_enabled(DRM_UT_DRIVER))                                  \
 		NV_PRINTK(info, &(drm)->client, f, ##a);                       \
 } while(0)
 #define NV_ATOMIC(drm,f,a...) do {                                             \
-	if (unlikely(drm_debug & DRM_UT_ATOMIC))                               \
+	if (drm_debug_enabled(DRM_UT_ATOMIC))                                  \
 		NV_PRINTK(info, &(drm)->client, f, ##a);                       \
 } while(0)