kasan, x86: don't rename memintrinsics in uninstrumented files

Now that memcpy/memset/memmove are no longer overridden by KASAN, we can
just use the normal symbol names in uninstrumented files.

Drop the preprocessor redefinitions.

Link: https://lkml.kernel.org/r/20230224085942.1791837-4-elver@google.com
Fixes: 69d4c0d ("entry, kasan, x86: Disallow overriding mem*() functions")
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linux Kernel Functional Testing <lkft@linaro.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: melver

arch/x86/include/asm/string_64.h

@@ -85,25 +85,6 @@ char *strcpy(char *dest, const char *src);
 char *strcat(char *dest, const char *src);
 int strcmp(const char *cs, const char *ct);
 
-#if (defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__))
-/*
- * For files that not instrumented (e.g. mm/slub.c) we
- * should use not instrumented version of mem* functions.
- */
-
-#undef memcpy
-#define memcpy(dst, src, len) __memcpy(dst, src, len)
-#undef memmove
-#define memmove(dst, src, len) __memmove(dst, src, len)
-#undef memset
-#define memset(s, c, n) __memset(s, c, n)
-
-#ifndef __NO_FORTIFY
-#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
-#endif
-
-#endif
-
 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 #define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
 void __memcpy_flushcache(void *dst, const void *src, size_t cnt);