Char: isicom: fix build warning

Fix this:
isicom.c: In function `isicom_probe':
isicom.c:1587: warning: `signature' may be used uninitialized in this function
by uninitialized_var(), because if the signature is not initialized in
reset_card(), we won't use it.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/isicom.c

@@ -1593,7 +1593,7 @@ static unsigned int card_count;
 static int __devinit isicom_probe(struct pci_dev *pdev,
 	const struct pci_device_id *ent)
 {
-	unsigned int signature, index;
+	unsigned int uninitialized_var(signature), index;
 	int retval = -EPERM;
 	struct isi_board *board = NULL;