libc/string: fix typo, CONFIGC_ARCH_STPNCPY
CONFIG'C'_ is a typo, let's remove 'C'.
*
****************************************************************************/
-#ifndef CONFIGC_ARCH_STPNCPY
+#ifndef CONFIG_ARCH_STPNCPY
FAR char *stpncpy(FAR char *dest, FAR const char *src, size_t n)
{
FAR char *end = dest + n; /* End of dest buffer + 1 byte */
