KVM: selftests: Add missing break between -e and -g option in dirty_log_perf_test

KVM: selftests: Add missing break between -e and -g option in dirty_log_perf_test

Passing -e option (Run VCPUs while dirty logging is being disabled) in
dirty_log_perf_test also unintentionally enables -g (Do not enable
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2). Add break between two switch case
logic.

Fixes: cfe12e64b065 ("KVM: selftests: Add an option to run vCPUs while disabling dirty logging")
Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221103191719.1559407-2-vipinsh@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>