target/avr: Fix buffer read in avr_print_insn

target/avr: Fix buffer read in avr_print_insn

Do not unconditionally attempt to read 4 bytes, as there
may only be 2 bytes remaining in the translator cache.

Cc: qemu-stable@nongnu.org
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20250325224403.4011975-2-richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
(cherry picked from commit 070a500cc0da70c1b4c62a6c95e41f0a1b19dc0b)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>