fs/squashfs: parameter check sqfs_read_metablock()

We should check if the incoming parameter file_mapping is not NULL instead
of checking after adding an offset.

Reported-by: Coverity CID 307210
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
1 file changed