Staging: brcm80211: sys: remove unneeded use of uintptr

uintptr shouldn't be used when you are just casting to a pointer anyway,
so remove it from these usages.

Cc: Brett Rudley <brudley@broadcom.com>
Cc: Henry Ptasinski <henryp@broadcom.com>
Cc: Nohee Ko <noheek@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>