llvm-scan-build: fix value stored to rc never read in hw/occ.c
llvm-scan-build: fix value stored to rc never read in hw/occ.c

hw/occ.c:278:2: warning: Value stored to 'rc' is never read
        rc = xscom_read(chip->id, XSCOM_ADDR_P8_EX_SLAVE(core, EX_PM_PPMCR), &tmp);
        ^    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hw/occ.c:309:2: warning: Value stored to 'rc' is never read
        rc = xscom_read(chip->id, XSCOM_ADDR_P8_EX_SLAVE(core, EX_PM_PPMSR), &tmp);
        ^    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

csmart/skiboot,legoater/skiboot,mikey/skiboot,stewart-ibm/skiboot,open-power/skiboot,legoater/skiboot,csmart/skiboot,shenki/skiboot,shenki/skiboot,qemu/skiboot,open-power/skiboot,stewart-ibm/skiboot,shenki/skiboot,legoater/skiboot,qemu/skiboot,legoater/skiboot,mikey/skiboot,legoater/skiboot,open-power/skiboot,open-power/skiboot,mikey/skiboot,shenki/skiboot,qemu/skiboot,qemu/skiboot,open-power/skiboot,shenki/skiboot,qemu/skiboot,stewart-ibm/skiboot,csmart/skiboot