ncpfs: don't allow negative timeouts

This code causes a static checker warning because it's a user controlled
variable where we cap the upper bound but not the lower bound.  Let's
return an -EINVAL for negative timeouts.

[akpm@linux-foundation.org: remove unneeded `else']
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jan Kara <jack@suse.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: David Howells <dhowells@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ncpfs/ioctl.c

@@ -525,6 +525,8 @@ static long __ncp_ioctl(struct inode *inode, unsigned int cmd, unsigned long arg
 			switch (rqdata.cmd) {
 				case NCP_LOCK_EX:
 				case NCP_LOCK_SH:
+						if (rqdata.timeout < 0)
+							return -EINVAL;
 						if (rqdata.timeout == 0)
 							rqdata.timeout = NCP_LOCK_DEFAULT_TIMEOUT;
 						else if (rqdata.timeout > NCP_LOCK_MAX_TIMEOUT)