staging: fix csr printk format warning

Fix printk format warning on i386/X86_32 by using 't' for ptrdiff_t.
Also builds cleanly on x86_64.

drivers/staging/csr/csr_wifi_hip_udi.c: In function 'unifi_print_status':
drivers/staging/csr/csr_wifi_hip_udi.c:151:27: warning: format '%ld' expects type 'long int', but argument 5 has type 'int'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/csr/csr_wifi_hip_udi.c

@@ -146,7 +146,7 @@ s32 unifi_print_status(card_t *card, char *str, s32 *remain)
                           (u16)card->to_host_signals_w);
     UNIFI_SNPRINTF_RET(p, remaining, written);
     written = scnprintf(p, remaining,
-                          "fh buffer contains: %d signals, %ld bytes\n",
+                          "fh buffer contains: %d signals, %td bytes\n",
                           card->fh_buffer.count,
                           card->fh_buffer.ptr - card->fh_buffer.buf);
     UNIFI_SNPRINTF_RET(p, remaining, written);