uboot-imx

fsl/sata: correctly identify failed malloc

After allocating sata->cmd_hdr_tbl_offset we have to check
this variable and not variable sata.

The problem was indicated by cppcheck.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>