tools/virtio: add a missing )
tools/virtio: add a missing )

Fixes the following build failure:

 cc -g -O2 -Wall -I. -I ../../usr/include/ -Wno-pointer-sign
   -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD
   -U_FORTIFY_SOURCE   -c -o virtio_test.o virtio_test.c
 virtio_test.c: In function ‘run_test’:
 virtio_test.c:176:7: error: expected ‘)’ before ‘r’
         r = -1;
         ^

Fixes: 53c18c9906441 (virtio_test: verify if virtqueue_kick() succeeded)
Cc: Heinz Graalfs <46cdc05a0738b8bf21bd6f3a5ef6c9b9523cce3c@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <4816dabf8db1bc6cac35b3a24cab2ff844b5b0c7@jms.id.au>
Acked-by: Michael S. Tsirkin <255103e50249e3d658441816e0597170ebfc16ef@redhat.com>
Signed-off-by: Rusty Russell <df9728c9e5104131c08c7adb03af425394842596@rustcorp.com.au>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs