Staging: cxt1e1: Fix externs should be avoided in .c files in comet.c

Fix checkpatch.pl issues with externs should be
avoided in comet.c

Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>