r100: Silence numerous unused this or that warnings

r100: Silence numerous unused this or that warnings

radeon_fbo.c: In function ‘radeon_map_renderbuffer_s8z24’:
radeon_fbo.c:147:50: warning: unused parameter ‘ctx’ [-Wunused-parameter]
 radeon_map_renderbuffer_s8z24(struct gl_context *ctx,
                                                  ^~~
radeon_fbo.c: In function ‘radeon_map_renderbuffer_z16’:
radeon_fbo.c:186:48: warning: unused parameter ‘ctx’ [-Wunused-parameter]
 radeon_map_renderbuffer_z16(struct gl_context *ctx,
                                                ^~~
radeon_fbo.c: In function ‘radeon_unmap_renderbuffer_s8z24’:
radeon_fbo.c:344:52: warning: unused parameter ‘ctx’ [-Wunused-parameter]
 radeon_unmap_renderbuffer_s8z24(struct gl_context *ctx,
                                                    ^~~
radeon_fbo.c: In function ‘radeon_unmap_renderbuffer_z16’:
radeon_fbo.c:377:50: warning: unused parameter ‘ctx’ [-Wunused-parameter]
 radeon_unmap_renderbuffer_z16(struct gl_context *ctx,
                                                  ^~~
radeon_fbo.c: In function ‘radeon_nop_alloc_storage’:
radeon_fbo.c:624:75: warning: unused parameter ‘rb’ [-Wunused-parameter]
 radeon_nop_alloc_storage(struct gl_context * ctx, struct gl_renderbuffer *rb,
                                                                           ^~
radeon_fbo.c:625:12: warning: unused parameter ‘internalFormat’ [-Wunused-parameter]
     GLenum internalFormat, GLuint width, GLuint height)
            ^~~~~~~~~~~~~~
radeon_fbo.c:625:35: warning: unused parameter ‘width’ [-Wunused-parameter]
     GLenum internalFormat, GLuint width, GLuint height)
                                   ^~~~~
radeon_fbo.c:625:49: warning: unused parameter ‘height’ [-Wunused-parameter]
     GLenum internalFormat, GLuint width, GLuint height)
                                                 ^~~~~~
radeon_fbo.c: In function ‘radeon_bind_framebuffer’:
radeon_fbo.c:696:74: warning: unused parameter ‘fbread’ [-Wunused-parameter]
                        struct gl_framebuffer *fb, struct gl_framebuffer *fbread)
                                                                          ^~~~~~
radeon_fbo.c: In function ‘radeon_validate_framebuffer’:
radeon_fbo.c:832:19: warning: unused variable ‘radeon’ [-Wunused-variable]
  radeonContextPtr radeon = RADEON_CONTEXT(ctx);
                   ^~~~~~

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>