tests: scsi reservation test shouldn't check host /dev/sda

Was failing in our CI

tests/cli-test-xml/compare/virt-install-many-devices.xml

@@ -162,7 +162,7 @@
     </disk>
     <disk type="block" device="lun">
       <driver name="qemu" type="raw"/>
-      <source dev="/dev/sda">
+      <source dev="/dev/disk-pool/diskvol7">
         <reservations managed="no">
           <source type="unix" path="/var/run/test/pr-helper0.sock" mode="client"/>
         </reservations>

tests/clitest.py

@@ -446,7 +446,7 @@ c.add_compare(""" \
 --disk /var,device=floppy,address.type=ccw,address.cssid=0xfe,address.ssid=0,address.devno=01 \
 --disk %(NEWIMG2)s,size=1,backing_store=/tmp/foo.img,backing_format=vmdk \
 --disk /tmp/brand-new.img,size=1,backing_store=/dev/default-pool/iso-vol \
---disk path=/dev/sda,device=lun,bus=scsi,reservations.managed=no,reservations.source.type=unix,reservations.source.path=/var/run/test/pr-helper0.sock,reservations.source.mode=client \
+--disk path=/dev/disk-pool/diskvol7,device=lun,bus=scsi,reservations.managed=no,reservations.source.type=unix,reservations.source.path=/var/run/test/pr-helper0.sock,reservations.source.mode=client \
 \
 --network user,mac=12:34:56:78:11:22,portgroup=foo,link_state=down,rom_bar=on,rom_file=/tmp/foo \
 --network bridge=foobar,model=virtio,driver_name=qemu,driver_queues=3 \

tests/testdriver.xml

@@ -1883,6 +1883,18 @@ ba</description>
       </permissions>
     </target>
   </volume>
+  <volume type='block'>
+    <name>diskvol7</name>
+    <capacity>1000000</capacity>
+    <allocation>50000</allocation>
+    <target>
+      <permissions>
+        <mode>0700</mode>
+        <owner>10736</owner>
+        <group>10736</group>
+      </permissions>
+    </target>
+  </volume>
 </pool>