gallizm/aux/util/u_format.c, u_debug_describe.c: Fix warnings

u_debug_describe.c: In function 'debug_describe_reference':
u_debug_describe.c:33:65: warning: unused parameter 'ptr' [-Wunused-
parameter]
 debug_describe_reference(char* buf, const struct pipe_reference*ptr)

u_format.c: In function 'util_format_is_float':
u_format.c:57:10: warning: comparison between signed and unsigned
integer expressions [-Wsign-compare]
    if (i == -1) {

v2: Replace VREND_UNUSED by UNUSED (Erik)

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/util/u_debug_describe.c

@@ -30,7 +30,7 @@
 #include "util/u_string.h"
 
 void
-debug_describe_reference(char* buf, const struct pipe_reference*ptr)
+debug_describe_reference(char* buf, UNUSED const struct pipe_reference*ptr)
 {
    strcpy(buf, "pipe_object");
 }

src/gallium/auxiliary/util/u_format.c

@@ -46,7 +46,7 @@ boolean
 util_format_is_float(enum pipe_format format)
 {
    const struct util_format_description *desc = util_format_description(format);
-   unsigned i;
+   int i;
 
    assert(desc);
    if (!desc) {