drm: Remove the prefix argument of drm_ut_debug_printk()

This is always DRM_NAME, so we can just make it part of the format
string instead of asking prink to do it for us.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index 0b1a912..9b14873 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -97,9 +97,7 @@
 }
 EXPORT_SYMBOL(drm_err);
 
-void drm_ut_debug_printk(const char *prefix,
-			 const char *function_name,
-			 const char *format, ...)
+void drm_ut_debug_printk(const char *function_name, const char *format, ...)
 {
 	struct va_format vaf;
 	va_list args;
@@ -108,7 +106,7 @@
 	vaf.fmt = format;
 	vaf.va = &args;
 
-	printk(KERN_DEBUG "[%s:%s], %pV", prefix, function_name, &vaf);
+	printk(KERN_DEBUG "[" DRM_NAME ":%s], %pV", function_name, &vaf);
 
 	va_end(args);
 }