s390/string: Remove optimized strncpy()

There are hardly any strncpy() users left, therefore drop the
optimized s390 variant.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Author: hcahca

arch/s390/include/asm/string.h

@@ -30,7 +30,6 @@ void *memmove(void *dest, const void *src, size_t n);
 #define __HAVE_ARCH_STRLCAT	/* arch function */
 #define __HAVE_ARCH_STRLEN	/* inline & arch function */
 #define __HAVE_ARCH_STRNCAT	/* arch function */
-#define __HAVE_ARCH_STRNCPY	/* arch function */
 #define __HAVE_ARCH_STRNLEN	/* inline & arch function */
 #define __HAVE_ARCH_STRSTR	/* arch function */
 #define __HAVE_ARCH_MEMSET16	/* arch function */
@@ -42,7 +41,6 @@ int memcmp(const void *s1, const void *s2, size_t n);
 int strcmp(const char *s1, const char *s2);
 size_t strlcat(char *dest, const char *src, size_t n);
 char *strncat(char *dest, const char *src, size_t n);
-char *strncpy(char *dest, const char *src, size_t n);
 char *strstr(const char *s1, const char *s2);
 #endif /* !defined(CONFIG_KASAN) && !defined(CONFIG_KMSAN) */
 

arch/s390/lib/string.c

@@ -101,26 +101,6 @@ char *strcpy(char *dest, const char *src)
 EXPORT_SYMBOL(strcpy);
 #endif
 
-/**
- * strncpy - Copy a length-limited, %NUL-terminated string
- * @dest: Where to copy the string to
- * @src: Where to copy the string from
- * @n: The maximum number of bytes to copy
- *
- * The result is not %NUL-terminated if the source exceeds
- * @n bytes.
- */
-#ifdef __HAVE_ARCH_STRNCPY
-char *strncpy(char *dest, const char *src, size_t n)
-{
-	size_t len = __strnend(src, n) - src;
-	memset(dest + len, 0, n - len);
-	memcpy(dest, src, len);
-	return dest;
-}
-EXPORT_SYMBOL(strncpy);
-#endif
-
 /**
  * strcat - Append one %NUL-terminated string to another
  * @dest: The string to be appended to
@@ -181,9 +161,6 @@ EXPORT_SYMBOL(strlcat);
  * @n: The maximum numbers of bytes to copy
  *
  * returns a pointer to @dest
- *
- * Note that in contrast to strncpy, strncat ensures the result is
- * terminated.
  */
 #ifdef __HAVE_ARCH_STRNCAT
 char *strncat(char *dest, const char *src, size_t n)