[CIFS] suppress duplicate warning

fs/cifs/dir.c: In function 'cifs_ci_compare':
fs/cifs/dir.c:582: warning: passing argument 1 of 'memcpy' discards
qualifiers from pointer target type

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>