msvcrt: Multi-byte characters handled incorrectly by MSVCRT_isleadbyte()

[Nagato]

Test case:
_mbspbrk("C:\\age\\マブラヴオルタネイティヴ\\Alternative.rio.ici", ";,|*?\"<>{}[]");
Should return NULL.

None of the Japanese characters are interpreted as multi-byte by
MSVCRT_isleadbyte() so when _mbspbrk reaches 'マ' (0x837D) it matches
the '}' (0x7D) from the match string with the second byte of 'マ'.

---
 dlls/msvcrt/ctype.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/dlls/msvcrt/ctype.c b/dlls/msvcrt/ctype.c
index 7e7d9f0..0fb3c41 100644
--- a/dlls/msvcrt/ctype.c
+++ b/dlls/msvcrt/ctype.c
@@ -138,7 +138,7 @@ int CDECL MSVCRT_isgraph(int c)
  */
 int CDECL MSVCRT_isleadbyte(int c)
 {
-  return _isctype( c, MSVCRT__LEADBYTE );
+    return _ismbblead(c);
 }