vrend_decode: use uints for sampler view decode

The protocol will never send negative numbers, so use uints
to avoid having to compare to 0 and other warnings.

Reviewed-by: Po-Hsien Wang <pwang@chromium.org>

src/vrend_decode.c

@@ -280,10 +280,10 @@ static int vrend_decode_set_vertex_buffers(struct vrend_decode_ctx *ctx, uint16_
 
 static int vrend_decode_set_sampler_views(struct vrend_decode_ctx *ctx, uint16_t length)
 {
-   int num_samps;
-   int i;
+   uint32_t num_samps;
+   uint32_t i;
    uint32_t shader_type;
-   int32_t start_slot;
+   uint32_t start_slot;
 
    if (length < 2)
       return EINVAL;

src/vrend_renderer.c

@@ -2142,7 +2142,7 @@ void vrend_set_num_vbo(struct vrend_context *ctx,
 
 void vrend_set_single_sampler_view(struct vrend_context *ctx,
                                    uint32_t shader_type,
-                                   int index,
+                                   uint32_t index,
                                    uint32_t handle)
 {
    struct vrend_sampler_view *view = NULL;

src/vrend_renderer.h

@@ -227,7 +227,7 @@ void vrend_set_num_sampler_views(struct vrend_context *ctx,
                                  int num_sampler_views);
 void vrend_set_single_sampler_view(struct vrend_context *ctx,
                                    uint32_t shader_type,
-                                   int index,
+                                   uint32_t index,
                                    uint32_t res_handle);
 
 void vrend_object_bind_blend(struct vrend_context *ctx,