fown: Fix compilation for older distros

Some of them (FC12 I debug on) doesn't have fown_ex stuff in their
libc. Add the missing declarations.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/types.h

@@ -204,4 +204,16 @@ enum kcmp_type {
 # define SCM_MAX_FD	253
 #endif
 
+#include <fcntl.h>
+
+#ifndef F_SETOWN_EX
+#define F_SETOWN_EX	15
+#define F_GETOWN_EX	16
+
+struct f_owner_ex {
+	int	type;
+	pid_t	pid;
+};
+#endif
+
 #endif /* CR_TYPES_H_ */

rbtree.c

@@ -2,6 +2,7 @@
  * RBtree implementation adopted from the Linux kernel sources.
  */
 
+#include <sys/types.h>
 #include "rbtree.h"
 
 static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)