Description of problem:
When trying to install using `debuginfo-install' all the available debuginfo
arches get installed while only the matching one should get installed.

Version-Release number of selected component (if applicable):
yum-3.2.12-3.fc9.noarch (Rawhide yum+rpm on F8)

How reproducible:
Always.

Steps to Reproduce:
1. Provide the test repository of dummy-{1,2}-0.fc8.{i386,x86_64} for yum.
2. Install dummy-1.0.fc8.x86_64.
3. rpm --qf '%{name}-%{version}-%{release}.%{arch}\n'  -qa 'dummy*'|sort
4. debuginfo-install --disablerepo='*' --enablerepo='dummy-*' dummy

Actual results:
# rpm --qf '%{name}-%{version}-%{release}.%{arch}\n'  -qa 'dummy*'|sort
dummy-1-0.fc8.x86_64
# debuginfo-install --disablerepo='*' --enablerepo='dummy-*' dummy
Loaded plugins: priorities, refresh-updatesd
dummy-2-debuginfo         100% |=========================|  951 B    00:00     
dummy-1                   100% |=========================|  951 B    00:00     
dummy-1-debuginfo         100% |=========================|  951 B    00:00     
dummy-2                   100% |=========================|  951 B    00:00     
...
--> Running transaction check
---> Package dummy-debuginfo.x86_64 0:1-0.fc8 set to be updated
---> Package dummy-debuginfo.i386 0:1-0.fc8 set to be updated
--> Finished Dependency Resolution

=============================================================================
 Package                 Arch       Version          Repository        Size 
=============================================================================
Installing:
 dummy-debuginfo         x86_64     1-0.fc8          dummy-1-debuginfo  4.8 k
 dummy-debuginfo         i386       1-0.fc8          dummy-1-debuginfo  5.0 k


Expected results:
# rpm --qf '%{name}-%{version}-%{release}.%{arch}\n'  -qa 'dummy*'|sort
dummy-1-0.fc8.x86_64
# debuginfo-install --disablerepo='*' --enablerepo='dummy-*' dummy
Loaded plugins: priorities, refresh-updatesd
dummy-2-debuginfo         100% |=========================|  951 B    00:00
dummy-1                   100% |=========================|  951 B    00:00
dummy-1-debuginfo         100% |=========================|  951 B    00:00
dummy-2                   100% |=========================|  951 B    00:00
...
--> Running transaction check
---> Package dummy-debuginfo.x86_64 0:1-0.fc8 set to be updated
--> Finished Dependency Resolution

=============================================================================
 Package                 Arch       Version          Repository        Size 
=============================================================================
Installing:
 dummy-debuginfo         x86_64     1-0.fc8          dummy-1-debuginfo  4.8 k


Additional info: