gdbstub: fix for commit 87f25c12bfeaaa0c41fb857713bbc7e8a9b757dc

This commit used the wrong check to prevent an assertion failure.
After this commit, you need to start a guest in the monitor, you
cannot use anymore the "c" command in the debugger.  This is
undesirable.  The commit's aim was to prevent a restart
after a KVM internal error or something like that; use
runstate_needs_reset() for that.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Message-id: 1370272015-9659-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
