Mark arguments to certain syscalls as being const

Mark arguments to certain system calls as being const where they should be but
aren't.  The list includes:

 (*) The filename arguments of various stat syscalls, execve(), various utimes
     syscalls and some mount syscalls.

 (*) The filename arguments of some syscall helpers relating to the above.

 (*) The buffer argument of various write syscalls.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
index 4393173..7427c0b 100644
--- a/arch/um/kernel/syscall.c
+++ b/arch/um/kernel/syscall.c
@@ -58,7 +58,7 @@
 
 	fs = get_fs();
 	set_fs(KERNEL_DS);
-	ret = um_execve((char *)filename, (char __user *__user *)argv,
+	ret = um_execve(filename, (char __user *__user *)argv,
 			(char __user *__user *) envp);
 	set_fs(fs);