zink: reorder create_stream_output_target to fix failure case leak

the previous version of this leaked a reference to the streamout buffer here

thanks to deltragon on my blog for pointing this out!

Fixes: 37778fcd9a35 ("zink: implement transform feedback support to finish off opengl 3.0")

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6457>
(cherry picked from commit 7971918924dd84c2f33a5b7f0a8bf0c23ed994d8)

.pick_status.json

diff --git a/.pick_status.json b/.pick_status.json
index 0a8f1ba..809f5ee 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -13,7 +13,7 @@
         "description": "zink: reorder create_stream_output_target to fix failure case leak",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": "37778fcd9a352430af0cd3b28a8776479a7c8380"
     },

src/gallium/drivers/zink/zink_context.c

diff --git a/src/gallium/drivers/zink/zink_context.c b/src/gallium/drivers/zink/zink_context.c
index 792027c..935c2ca 100644
--- a/src/gallium/drivers/zink/zink_context.c
+++ b/src/gallium/drivers/zink/zink_context.c
@@ -1048,12 +1048,6 @@
    if (!t)
       return NULL;
 
-   t->base.reference.count = 1;
-   t->base.context = pctx;
-   pipe_resource_reference(&t->base.buffer, pres);
-   t->base.buffer_offset = buffer_offset;
-   t->base.buffer_size = buffer_size;
-
    /* using PIPE_BIND_CUSTOM here lets us create a custom pipe buffer resource,
     * which allows us to differentiate and use VK_BUFFER_USAGE_TRANSFORM_FEEDBACK_COUNTER_BUFFER_BIT_EXT
     * as we must for this case
@@ -1064,6 +1058,12 @@
       return NULL;
    }
 
+   t->base.reference.count = 1;
+   t->base.context = pctx;
+   pipe_resource_reference(&t->base.buffer, pres);
+   t->base.buffer_offset = buffer_offset;
+   t->base.buffer_size = buffer_size;
+
    return &t->base;
 }