--*dir) option pattern precede --{en,dis}able-usb-redir) patterns in the
option analysis switch, making the latter options have no effect.

There were some --*dir that are supported by Autoconf and not by QEMU configure.
The aim was to let QEMU packagers use the rpm (or similar) macro that overrides
directories for their distribution.

Replace --*dir with exact option names.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>