c_write_operations.cc: fix some ioctx resource leaks

CID 1160833 (#3 of 3): Resource leak (RESOURCE_LEAK)
 leaked_storage: Variable "ioctx" going out of scope leaks the storage
 it points to

CID 1160835 (#3 of 3): Resource leak (RESOURCE_LEAK)
 leaked_storage: Variable "ioctx" going out of scope leaks the storage
 it points to.

CID 1188156 (#5 of 5): Resource leak (RESOURCE_LEAK)
 leaked_storage: Variable "ioctx" going out of scope leaks the storage
 it points to.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>