[CIFS] Correct keys dependency for cifs kerberos support

Must also depend on CIFS ...

Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/Kconfig b/fs/Kconfig
index f042710..3fab390 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -1984,7 +1984,7 @@
 
 config CIFS_UPCALL
 	  bool "Kerberos/SPNEGO advanced session setup (EXPERIMENTAL)"
-	  depends on KEYS
+	  depends on CIFS && KEYS
 	  help
 	    Enables an upcall mechanism for CIFS which accesses
 	    userspace helper utilities to provide SPNEGO packaged (RFC 4178)