fs/file: more unsigned file descriptors

Propagate unsignedness for grand total of 149 bytes:

	$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
	add/remove: 0/0 grow/shrink: 0/10 up/down: 0/-149 (-149)
	function                                     old     new   delta
	set_close_on_exec                             99      98      -1
	put_files_struct                             201     200      -1
	get_close_on_exec                             59      58      -1
	do_prlimit                                   498     497      -1
	do_execveat_common.isra                     1662    1661      -1
	__close_fd                                   178     173      -5
	do_dup2                                      219     204     -15
	seq_show                                     685     660     -25
	__alloc_fd                                   384     357     -27
	dup_fd                                       718     646     -72

It mostly comes from converting "unsigned int" to "long" for bit operations.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index a13bbda..d663210 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -108,7 +108,7 @@
 extern int percpu_pagelist_fraction;
 extern int compat_log;
 extern int latencytop_enabled;
-extern int sysctl_nr_open_min, sysctl_nr_open_max;
+extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
 #ifndef CONFIG_MMU
 extern int sysctl_nr_trim_pages;
 #endif
@@ -1692,7 +1692,7 @@
 	{
 		.procname	= "nr_open",
 		.data		= &sysctl_nr_open,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= &sysctl_nr_open_min,