[CIFS] remove unused funtion compile warning when experimental off

get rid of couple of unused function warnings which
show up when CONFIG_CIFS_EXPERIMENTAL is not defined - wrap them in
#ifdef CONFIG_CIFS_EXPERIMENTAL. Patch against current git.

Signed-off-by: Parag Warudkar <kernel-stuff@comcast.net>
Signed-off-by: Steve French <sfrench@us.ibm.com>