hw/misc: use extract64 instead of 1 << i

1 << i is casted to uint64_t while bitwise and with val.
So this value may become 0xffffffff80000000 but only
31th "start" bit is required.
Use the bitfield extract() API instead.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Tigran Sogomonian <[email protected]>
Reviewed-by: Alex Bennée <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Bonzini <[email protected]>

Author: Tigran Sogomonian

hw/misc/mps2-fpgaio.c

@@ -198,7 +198,7 @@ static void mps2_fpgaio_write(void *opaque, hwaddr offset, uint64_t value,
 
             s->led0 = value & MAKE_64BIT_MASK(0, s->num_leds);
             for (i = 0; i < s->num_leds; i++) {
-                led_set_state(s->led[i], value & (1 << i));
+                led_set_state(s->led[i], extract64(value, i, 1));
             }
         }
         break;