staging: apf: Correct kernel-doc structure for xlnk.c

staging: apf: Correct kernel-doc structure for xlnk.c

This patch eliminates warnings associated with kernel-doc
formatting in the apf driver.  It does this by removing the
partial comment was being detected as being an attempt at a
kernel-doc comment.  This patch is only meant to resolve
warnings.  Follow up patches will be to comment the driver.

Signed-off-by: Michael Gill <michael.gill@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>