powerpc/boot: Fix missing check of lseek() return value
This is detected by Coverity scan: CID: 1440481 Signed-off-by: Bo YU <tsu.yubo@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This is detected by Coverity scan: CID: 1440481 Signed-off-by: Bo YU <tsu.yubo@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>