staging:wlan-ng: fix sparse warnings

drivers/staging/wlan-ng/prism2fw.c:240:5: warning: symbol 'prism2_fwapply' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:379:5: warning: symbol 'crcimage' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:443:6: warning: symbol 'free_chunks' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:465:6: warning: symbol 'free_srecs' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:492:5: warning: symbol 'mkimage' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:585:5: warning: symbol 'mkpdrlist' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:659:5: warning: symbol 'plugimage' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:767:5: warning: symbol 'read_cardpda' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:857:5: warning: symbol 'read_fwfile' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:981:5: warning: symbol 'writeimage' was not declared. Should it be static?
drivers/staging/wlan-ng/prism2fw.c:1133:5: warning: symbol 'validate_identity' was not declared. Should it be static?

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>