qemuBuildRBDSecinfoURI: Use virSecureEraseString instead of VIR_AUTODISPOSE_STR
qemuBuildRBDSecinfoURI: Use virSecureEraseString instead of VIR_AUTODISPOSE_STR

In this instance attempting to be correct is really pointless since the
secret is formatted into another string which is not erased securely and
then put on the commandline.

Keep the secure handling for correctness.

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

crobinso/libvirt,zippy2/libvirt,libvirt/libvirt,libvirt/libvirt,nertpinx/libvirt,crobinso/libvirt,nertpinx/libvirt,olafhering/libvirt,libvirt/libvirt,zippy2/libvirt,olafhering/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,olafhering/libvirt,crobinso/libvirt,nertpinx/libvirt,nertpinx/libvirt,jfehlig/libvirt,jfehlig/libvirt,jfehlig/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt