By freeing filename (which is either NULL or the previous iteration of
this argument). This implements a semantic where the last --pagefile
given on the command line takes precedence.
This is the same semantic as the other options have.
CID: 1198792
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>