CIFS: Fix compile error with __init in cifs_init_dns_resolver() definition

An allmodconfig compile on ppc64 with 2.6.32.17 currently gives this error

fs/cifs/dns_resolve.h:27: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'cifs_init_dns_resolver'

This adds the correct header file to fix this.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

fs/cifs/dns_resolve.h

@@ -24,6 +24,8 @@
 #define _DNS_RESOLVE_H
 
 #ifdef __KERNEL__
+#include <linux/module.h>
+
 extern int __init cifs_init_dns_resolver(void);
 extern void cifs_exit_dns_resolver(void);
 extern int dns_resolve_server_name_to_ip(const char *unc, char **ip_addr);