ncpfs: fix wrong check in __ncp_ioctl()

We want to check for s_inode's existence, not inode's one (inode is always
valid in this function).

This takes care of the following entry from Dan's list:

fs/ncpfs/ioctl.c +445 __ncp_ioctl(180) warning: variable derefenced before check 'inode'
Reported-by: Dan Carpenter <error27@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ncpfs/ioctl.c

@@ -442,7 +442,7 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
 			if (dentry) {
 				struct inode* s_inode = dentry->d_inode;
 				
-				if (inode) {
+				if (s_inode) {
 					NCP_FINFO(s_inode)->volNumber = vnum;
 					NCP_FINFO(s_inode)->dirEntNum = de;
 					NCP_FINFO(s_inode)->DosDirNum = dosde;