activate_fw: fix typo
activate_fw: fix typo

The default case in error handler should return code 6, not 4.

Signed-off-by: Chandni Verma <dad063f8ade782763c74e4953e61405f236df268@linux.vnet.ibm.com>

shenki/powerpc-utils,shenki/powerpc-utils,shenki/powerpc-utils