Boot_order: ensure only 1 repo is used to get boot.iso

Issue:
VMStartError: VM 'avocado-vt-vm1' failed to start: error:
Failed to start domain 'avocado-vt-vm1'error: Cannot access storage file
'/var/lib/avocado/data/avocado-vt/boot.iso': No such file or directory(exit status: 1)

Fix:
This issue is caused by multiple repos being fetched and then their urls being concatenated together.
The fix is to ensure that only 1 repo is fetched (the last result),
which can in turn get the boot.iso file.

libvirt/tests/src/guest_os_booting/boot_order/boot_from_cdrom_device.py

@@ -30,7 +30,7 @@ def parse_cdroms_attrs(params):
         cdrom_attrs_list.append(cdrom2_attrs)
 
     if cdrom1_attrs.get('source') or cdrom2_attrs.get('source'):
-        cmd = "dnf repolist -v enabled |awk '/Repo-baseurl.*composes.*BaseOS.*os/ {print $NF}'"
+        cmd = "dnf repolist -v enabled |awk '/Repo-baseurl.*composes.*BaseOS.*os/ {res=$NF} END{print res}'"
         repo_url = process.run(cmd, shell=True).stdout_text.strip()
         boot_img_url = os.path.join(repo_url, 'images', 'boot.iso')
         if os.path.exists(boot_img_path):

libvirt/tests/src/guest_os_booting/boot_order/boot_with_multiple_boot_dev.py

@@ -47,7 +47,7 @@ def prepare_device(params, vm_name, bootable_device):
         libvirt_vmxml.modify_vm_device(vmxml, 'disk', disk_dict)
     if bootable_device == "cdrom_bootable":
         cdrom_path = os.path.join(data_dir.get_data_dir(), 'images', 'boot.iso')
-        cmd = "dnf repolist -v enabled |awk '/Repo-baseurl.*composes.*BaseOS.*os/ {print $NF}'"
+        cmd = "dnf repolist -v enabled |awk '/Repo-baseurl.*composes.*BaseOS.*os/ {res=$NF} END{print res}'"
         repo_url = process.run(cmd, shell=True).stdout_text.strip()
         boot_img_url = os.path.join(repo_url, 'images', 'boot.iso')
         download.get_file(boot_img_url, cdrom_path)

libvirt/tests/src/guest_os_booting/boot_order/boot_with_multiple_boot_order.py

@@ -42,7 +42,7 @@ def prepare_device_attrs(params, vm_name, bootable_device):
         file_list.append(disk_image)
     if bootable_device == "cdrom_bootable":
         cdrom_path = os.path.join(data_dir.get_data_dir(), 'images', 'boot.iso')
-        cmd = "dnf repolist -v enabled |awk '/Repo-baseurl.*composes.*BaseOS.*os/ {print $NF}'"
+        cmd = "dnf repolist -v enabled |awk '/Repo-baseurl.*composes.*BaseOS.*os/ {res=$NF} END{print res}'"
         repo_url = process.run(cmd, shell=True).stdout_text.strip()
         boot_img_url = os.path.join(repo_url, 'images', 'boot.iso')
         download.get_file(boot_img_url, cdrom_path)