monitor: Trim some trailing space from human-readable output

I noticed -cpu help printing enough trailing spaces to make the output
at least 84 characters wide.  Looks ugly unless the terminal is wider.
Ugly or not, trailing spaces are stupid.

The culprit is this line in x86_cpu_list_entry():

    qemu_printf("x86 %-20s  %-58s\n", name, desc);

This prints a string with minimum field left-justified right before a
newline.  Change it to

    qemu_printf("x86 %-20s  %s\n", name, desc);

which avoids the trailing spaces and is simpler to boot.

A search for the pattern with "git-grep -E '%-[0-9]+s\\n'" found a few
more instances.  Change them similarly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Message-Id: <20211009152401.2982862-1-armbru@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>