msvcrt: Don't forward memchr to ntdll.

dlls/msvcrt/msvcrt.spec

@@ -1367,7 +1367,7 @@
 @ cdecl mbstowcs(ptr str long) MSVCRT_mbstowcs
 @ cdecl mbstowcs_s(ptr ptr long str long) MSVCRT__mbstowcs_s
 @ cdecl mbtowc(ptr str long) MSVCRT_mbtowc
-@ cdecl memchr(ptr long long) ntdll.memchr
+@ cdecl memchr(ptr long long) MSVCRT_memchr
 @ cdecl memcmp(ptr ptr long) ntdll.memcmp
 @ cdecl memcpy(ptr ptr long) MSVCRT_memcpy
 @ cdecl memcpy_s(ptr long ptr long)

dlls/msvcrt/string.c

@@ -1616,6 +1616,14 @@ char* __cdecl MSVCRT_strchr(const char *str, int c)
 }
 
 /*********************************************************************
+ *                  memchr   (MSVCRT.@)
+ */
+void* __cdecl MSVCRT_memchr(const void *ptr, int c, MSVCRT_size_t n)
+{
+    return memchr(ptr, c, n);
+}
+
+/*********************************************************************
  *                  strncmp   (MSVCRT.@)
  */
 int __cdecl MSVCRT_strncmp(const char *str1, const char *str2, MSVCRT_size_t len)