We need to mock virQEMUCapsGetKVMSupportsSecureGuest only if compiling
with QEMU otherwise compilation will fail with error:
/usr/lib/gcc/i686-w64-mingw32/11.1.1/../../../../i686-w64-mingw32/bin/ld: tests/libdomaincapsmock.dll.p/domaincapsmock.c.obj: in function `virQEMUCapsGetKVMSupportsSecureGuest':
/builds/libvirt/libvirt/build/../tests/domaincapsmock.c:40: undefined reference to `virQEMUCapsGet'
/usr/lib/gcc/i686-w64-mingw32/11.1.1/../../../../i686-w64-mingw32/bin/ld: /builds/libvirt/libvirt/build/../tests/domaincapsmock.c:41: undefined reference to `virQEMUCapsGet'
Fixes: 248a30c0c0ec2610e8fa2bbbc98da6d06978ad2e Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>