aco: silent checking if clrxdisasm is available

Otherwise, this is reported a ton of times and the CI output is
unusable.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27136>

src/amd/compiler/aco_print_asm.cpp

@@ -412,7 +412,7 @@ check_print_asm_support(Program* program)
 #ifndef _WIN32
    /* Check if CLRX disassembler binary is available and can disassemble the program */
    return to_clrx_device_name(program->gfx_level, program->family) &&
-          system("clrxdisasm --version") == 0;
+          system("clrxdisasm --version > /dev/null 2>&1") == 0;
 #else
    return false;
 #endif