r600: fix shader blob memory leak

Fixes: 5b205ef
   r600: Store nir shaders serialized to save memory

Direct leak of 4096 byte(s) in 1 object(s) allocated from:
    #0 0x7faf89c3bb48 in __interceptor_realloc (/usr/lib64/libasan.so.6+0xb1b48)
    android-rpi#1 0x7faf7be5981d in grow_to_fit ../src/util/blob.c:67
    android-rpi#2 0x7faf7be5a538 in grow_to_fit ../src/util/blob.c:49
    android-rpi#3 0x7faf7be5a538 in blob_reserve_bytes ../src/util/blob.c:177
    #4 0x7faf7be5a538 in blob_reserve_uint32 ../src/util/blob.c:190
    #5 0x7faf7d248a8c in nir_serialize ../src/compiler/nir/nir_serialize.c:2109
    #6 0x7faf7df4fdbb in r600_pipe_shader_create ../src/gallium/drivers/r600/r600_shader.c:401

Signed-off-by: Patrick Lerda <[email protected]>
Reviewed-by: Gert Wollny <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21443>
(cherry picked from commit 9b4eb73)

Author: Patrick Lerda

.pick_status.json

@@ -139,7 +139,7 @@
         "description": "r600: fix shader blob memory leak",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "5b205ef41307406983ffac829ae423d08f7527bc"
     },

src/gallium/drivers/r600/r600_shader.c

@@ -402,6 +402,7 @@ int r600_pipe_shader_create(struct pipe_context *ctx,
 		sel->nir_blob = malloc(blob.size);
 		memcpy(sel->nir_blob, blob.data, blob.size);
 		sel->nir_blob_size = blob.size;
+		blob_finish(&blob);
 	}
 	ralloc_free(sel->nir);
 	sel->nir = NULL;