staging wlan-ng: fix type mismatch warnings in mkpdrlist()

struct  hfa384x_pdrec len and code fields as clearly little endian,
mark both fields as such. pda->buf is also clearly little endian.

Fixes sparse warnings:

  drivers/staging/wlan-ng/prism2fw.c:613:16: warning: cast to restricted __le16
  drivers/staging/wlan-ng/prism2fw.c:616:21: warning: cast to restricted __le16
  drivers/staging/wlan-ng/prism2fw.c:625:21: warning: cast to restricted __le16
Signed-off-by: NMaciek Borzecki <maciek.borzecki@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/hfa384x.h

@@ -1078,8 +1078,8 @@ struct hfa384x_pdr_end_of_pda {
 } __packed;
 
 struct hfa384x_pdrec {
-	u16 len;		/* in words */
-	u16 code;
+	__le16 len;		/* in words */
+	__le16 code;
 	union pdr {
 		struct hfa384x_pdr_pcb_partnum pcb_partnum;
 		struct hfa384x_pdr_pcb_tracenum pcb_tracenum;

drivers/staging/wlan-ng/prism2fw.c

@@ -604,7 +604,7 @@ static int mkimage(struct imgchunk *clist, unsigned int *ccnt)
  */
 static int mkpdrlist(struct pda *pda)
 {
-	u16 *pda16 = (u16 *)pda->buf;
+	__le16 *pda16 = (__le16 *)pda->buf;
 	int curroff;		/* in 'words' */
 
 	pda->nrec = 0;