drm/i915: switch ring->id to be a real id

... and add a helpr function for the places where we want a flag.

This way we can use ring->id to index into arrays.

v2: Resurrect the missing beautification-space Chris Wilson noted.
I'm moving this space around because I'll reuse ring_str in the next
patch.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 6c3be86..9c5db4e 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -669,9 +669,9 @@
 static const char *ring_str(int ring)
 {
 	switch (ring) {
-	case RING_RENDER: return " render";
-	case RING_BSD: return " bsd";
-	case RING_BLT: return " blt";
+	case RCS: return "render";
+	case VCS: return "bsd";
+	case BCS: return "blt";
 	default: return "";
 	}
 }
@@ -714,7 +714,7 @@
 	seq_printf(m, "%s [%d]:\n", name, count);
 
 	while (count--) {
-		seq_printf(m, "  %08x %8u %04x %04x %08x%s%s%s%s%s%s",
+		seq_printf(m, "  %08x %8u %04x %04x %08x%s%s%s%s%s%s%s",
 			   err->gtt_offset,
 			   err->size,
 			   err->read_domains,
@@ -724,6 +724,7 @@
 			   tiling_flag(err->tiling),
 			   dirty_flag(err->dirty),
 			   purgeable_flag(err->purgeable),
+			   err->ring != -1 ? " " : "",
 			   ring_str(err->ring),
 			   cache_level_str(err->cache_level));