um: kill useless include of user.h

everything in USER_OBJ gets it via -include user.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/hostfs/hostfs_user.c

@@ -16,7 +16,6 @@
 #include <sys/vfs.h>
 #include "hostfs.h"
 #include "os.h"
-#include "user.h"
 #include <utime.h>
 
 static void stat64_to_hostfs(const struct stat64 *buf, struct hostfs_stat *p)