hw: Fix qemu_allocate_irqs() leaks

hw: Fix qemu_allocate_irqs() leaks

Replace qemu_allocate_irqs(foo, bar, 1)[0]
with qemu_allocate_irq(foo, bar, 0).

This avoids leaking the dereferenced qemu_irq *.

Cc: Markus Armbruster <[email protected]>
Reviewed-by: Peter Crosthwaite <[email protected]>
Reviewed-by: Peter Maydell <[email protected]>
Signed-off-by: Andreas Färber <[email protected]>
[PC Changes:
 * Applied change to instance in sh4/sh7750.c
]
Signed-off-by: Peter Crosthwaite <[email protected]>
Reviewed-by: Kirill Batuzov <[email protected]>
[AF: Fix IRQ index in sh4/sh7750.c]
Cc: [email protected]
Signed-off-by: Andreas Färber <[email protected]>