tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy'

To bring in the change made in this cset:

Fixes: a7bea830 ("x86/asm/64: Use 32-bit XOR to zero registers")

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  LD       /tmp/build/perf/bench/perf-in.o
  LD       /tmp/build/perf/perf-in.o
  LINK     /tmp/build/perf/perf

Silencing this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
  diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-sad22dudoz71qr3tsnlqtkia@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/arch/x86/lib/memcpy_64.S

@@ -256,7 +256,7 @@ ENTRY(__memcpy_mcsafe)
 
 	/* Copy successful. Return zero */
 .L_done_memcpy_trap:
-	xorq %rax, %rax
+	xorl %eax, %eax
 	ret
 ENDPROC(__memcpy_mcsafe)
 EXPORT_SYMBOL_GPL(__memcpy_mcsafe)