gallium/aux/tgsi/tgsi_scan.c: Fix warnings

tgsi_scan.c:37:0:
tgsi_scan.c: In function 'tgsi_scan_shader':
tgsi_scan.c:212:46: warning: comparison between signed and unsigned
integer expressions [-Wsign-compare]
        assert(src->Register.Index < Elements(info->is_msaa_sampler));

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Signed-off-by: Jakob Bornecrantz <jakob@collabora.com>

src/gallium/auxiliary/tgsi/tgsi_scan.c

@@ -209,7 +209,7 @@ tgsi_scan_shader(const struct tgsi_token *tokens,
                /* MSAA samplers */
                if (src->Register.File == TGSI_FILE_SAMPLER) {
                   assert(fullinst->Instruction.Texture);
-                  assert(src->Register.Index < Elements(info->is_msaa_sampler));
+                  assert((unsigned)src->Register.Index < Elements(info->is_msaa_sampler));
 
                   if (fullinst->Instruction.Texture &&
                       (fullinst->Texture.Texture == TGSI_TEXTURE_2D_MSAA ||