USB: storage: Drop an unneeded a NULL test

In each case, the NULL test is not necessary because the function is static
and at the only places where it is called, the us argument has already been
dereferenced.

The semantic patch that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
type T;
expression E,E1;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E=E1
      when != i
  if (E == NULL||...) S
+ i = E->fld;
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/storage/datafab.c

@@ -334,7 +334,7 @@ static int datafab_determine_lun(struct us_data *us,
 	unsigned char *buf;
 	int count = 0, rc;
 
-	if (!us || !info)
+	if (!info)
 		return USB_STOR_TRANSPORT_ERROR;
 
 	memcpy(command, scommand, 8);
@@ -399,7 +399,7 @@ static int datafab_id_device(struct us_data *us,
 	unsigned char *reply;
 	int rc;
 
-	if (!us || !info)
+	if (!info)
 		return USB_STOR_TRANSPORT_ERROR;
 
 	if (info->lun == -1) {

drivers/usb/storage/jumpshot.c

@@ -335,7 +335,7 @@ static int jumpshot_id_device(struct us_data *us,
 	unsigned char *reply;
 	int 	 rc;
 
-	if (!us || !info)
+	if (!info)
 		return USB_STOR_TRANSPORT_ERROR;
 
 	command[0] = 0xE0;