staging: wimax: Fix block comment style issue in stack.c

This change fixes a checkpatch warning for "Block comments use
* on subsequent lines". It removes the unnecessary block comment.

Signed-off-by: Amrit Khera <amritkhera98@gmail.com>
Link: https://lore.kernel.org/r/20210222101541.2571-1-amritkhera98@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>