KVM: Implement strchr() and basic sprintf()

Add basic implementation of sprintf() that supports string, pointer
and integer arguments but without advanced formatting options like
field alignment and padding.

Link: https://lore.kernel.org/ltp/20240514120713.12308-3-mdoucha@suse.cz/
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Martin Doucha <mdoucha@suse.cz>
2 files changed