r300g: Remove extra printf format specifiers.
Fix warning reported by Coverity Scan.
Missing argument to printf format specifier (PRINTF_ARGS)
missing_argument: No argument for format specifier %s.
Fixes: 04c1536bf7ab ("r300g: rasterizer debug logging")
Fixes: 85efb2fff0d4 ("r300g: try to use color varyings for texcoords if max texcoord limit is exceeded")
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
cc: @mareko