renderer: fix a couple of shadowed variable declarations.

This fixes a couple of -Wshadow warnings.
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/vrend_renderer.c

@@ -6064,9 +6064,9 @@ void vrend_renderer_fill_caps(uint32_t set, uint32_t version,
 
 
    if (epoxy_has_gl_extension("GL_ARB_vertex_type_10f_11f_11f_rev")) {
-      int i = VIRGL_FORMAT_R11G11B10_FLOAT;
-      uint32_t offset = i / 32;
-      uint32_t index = i % 32;
+      int val = VIRGL_FORMAT_R11G11B10_FLOAT;
+      uint32_t offset = val / 32;
+      uint32_t index = val % 32;
 
       caps->v1.vertexbuffer.bitmask[offset] |= (1 << index);
    }

src/vrend_shader.c

@@ -910,8 +910,8 @@ static int emit_buf(struct dump_ctx *ctx, const char *buf)
 }
 
 #define EMIT_BUF_WITH_RET(ctx, buf) do {        \
-      int ret = emit_buf((ctx), (buf));                \
-      if (ret) return FALSE;                        \
+      int _ret = emit_buf((ctx), (buf));                \
+      if (_ret) return FALSE;                        \
    } while(0)
 
 static int translate_tex(struct dump_ctx *ctx,