[CIFS] fix ls -l warning on dirs when POSIX ACLs enabled.

Fixed by not returning -ERANCE error on null buffer on QueryACL 
(getxattr for ACLs will null buffer, zero len queries size)

Signed-off-by: Steve French (sfrench@us.ibm.com)

fs/cifs/cifssmb.c

@@ -1638,17 +1638,17 @@ static int cifs_copy_posix_acl(char * trgt,char * src, const int buflen,const in
 	}
 
 	size = posix_acl_xattr_size(count);
-	if(size > buflen) {
-	/* BB should we fill in as much data as we can first? */
-	/* seems odd that API was not designed so one could query ACL size */
+	if((buflen == 0) || (local_acl == NULL)) {
+		/* used to query ACL EA size */				
+	} else if(size > buflen) {
 		return -ERANGE;
-	}
-
+	} else /* buffer big enough */ {
 		local_acl->a_version = POSIX_ACL_XATTR_VERSION;
 		for(i = 0;i < count ;i++) {
 			cifs_convert_ace(&local_acl->a_entries[i],pACE);
 			pACE ++;
 		}
+	}
 	return size;
 }