qemu_process: Use consistent name for stop process function

qemu_process: Use consistent name for stop process function

s/qemuProcessQMPAbort/qemuProcessQMPStop/ applied to change function
name used to stop QEMU processes in process code moved from
qemu_capabilities.

No functionality change.

The new name, qemuProcessQMPStop, is consistent with the existing
function qemuProcessStop used to stop Domain processes.

Signed-off-by: Chris Venteicher <cventeic@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>