drm/i915: Make the hexdump row offset visually distinct

Currently we use %08x for the row offset, and %08x for the binary
contents of the buffer. This makes it very easily to confuse the two, so
switch to using [%04x] for the start-of-row offset.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180614094103.18025-3-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_engine_cs.c

@@ -1258,7 +1258,7 @@ static void hexdump(struct drm_printer *m, const void *buf, size_t len)
 						rowsize, sizeof(u32),
 						line, sizeof(line),
 						false) >= sizeof(line));
-		drm_printf(m, "%08zx %s\n", pos, line);
+		drm_printf(m, "[%04zx] %s\n", pos, line);
 
 		prev = buf + pos;
 		skip = false;