make arrayname size a bit larger

[addr%d] could in theory be [addr65536] so needs a few more bytes.

Fixes warning:
vrend_shader.c: In function ‘iter_instruction’:
vrend_shader.c:1861:38: warning: ‘%d’ directive writing between 1 and 6 bytes into a region of size 4 [-Wformat-overflow=]
             sprintf(arrayname, "[addr%d]", src->DimIndirect.Index);
                                      ^~
vrend_shader.c:1861:32: note: directive argument in the range [-32768, 32767]
             sprintf(arrayname, "[addr%d]", src->DimIndirect.Index);
                                ^~~~~~~~~~
vrend_shader.c:1861:13: note: ‘sprintf’ output between 8 and 13 bytes into a destination of size 9
             sprintf(arrayname, "[addr%d]", src->DimIndirect.Index);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Reviewed-by: Elie Tournier <elie.tournier@collabora.com>

src/vrend_shader.c

@@ -1842,7 +1842,7 @@ iter_instruction(struct tgsi_iterate_context *iter,
       const struct tgsi_full_src_register *src = &inst->Src[i];
       char swizzle[8] = {0};
       char prefix[6] = {0};
-      char arrayname[9] = {0};
+      char arrayname[16] = {0};
       int swz_idx = 0, pre_idx = 0;
       boolean isabsolute = src->Register.Absolute;