libflash: Fix Coverity defect 97867
libflash: Fix Coverity defect 97867

CID 97867 (#1 of 1): Uninitialized scalar variable (UNINIT)
5. uninit_use: Using uninitialized value rc.

Signed-off-by: Cyril Bur <6ce38dade8c4b52fd55c193fae70fd1d1275c3c3@au1.ibm.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

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