inotify: fix type errors in interfaces

The problems lie in the types used for some inotify interfaces, both at the kernel level and at the glibc level. This mail addresses the kernel problem. I will follow up with some suggestions for glibc changes.

For the sys_inotify_rm_watch() interface, the type of the 'wd' argument is
currently 'u32', it should be '__s32' .  That is Robert's suggestion, and
is consistent with the other declarations of watch descriptors in the
kernel source, in particular, the inotify_event structure in
include/linux/inotify.h:

struct inotify_event {
        __s32           wd;             /* watch descriptor */
        __u32           mask;           /* watch mask */
        __u32           cookie;         /* cookie to synchronize two events */
        __u32           len;            /* length (including nulls) of name */
        char            name[0];        /* stub for possible name */
};

The patch makes the changes needed for inotify_rm_watch().
Signed-off-by: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Robert Love <rlove@google.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/notify/inotify/inotify_user.c

@@ -704,7 +704,7 @@ fput_and_out:
 	return ret;
 }
 
-asmlinkage long sys_inotify_rm_watch(int fd, u32 wd)
+asmlinkage long sys_inotify_rm_watch(int fd, __s32 wd)
 {
 	struct file *filp;
 	struct inotify_device *dev;

include/linux/syscalls.h

@@ -549,7 +549,7 @@ asmlinkage long sys_inotify_init(void);
 asmlinkage long sys_inotify_init1(int flags);
 asmlinkage long sys_inotify_add_watch(int fd, const char __user *path,
 					u32 mask);
-asmlinkage long sys_inotify_rm_watch(int fd, u32 wd);
+asmlinkage long sys_inotify_rm_watch(int fd, __s32 wd);
 
 asmlinkage long sys_spu_run(int fd, __u32 __user *unpc,
 				 __u32 __user *ustatus);