x86: Remove "%!" before ret

x86: Remove "%!" before ret

Before MPX was removed, "%!" was mapped to

        case '!':
          if (ix86_bnd_prefixed_insn_p (current_output_insn))
            fputs ("bnd ", file);
          return;

After CET was added and MPX was removed, "%!" was mapped to

       case '!':
          if (ix86_notrack_prefixed_insn_p (current_output_insn))
            fputs ("notrack ", file);
          return;

ix86_notrack_prefixed_insn_p always returns false on ret since the
notrack prefix is only for indirect branches.  Remove the unused "%!"
before ret.

	PR target/103307
	* config/i386/i386.c (ix86_code_end): Remove "%!" before ret.
	(ix86_output_function_return): Likewise.
	* config/i386/i386.md (simple_return_pop_internal): Likewise.