ARM: meson: fixup error on efuse commands return

All `sm efuseread/efusewrite` commands exit with an error, even if the fuse
have actually been dealt with correctly.

This is because the smc call return the size it actually processed but this
result is checked against 0.

Return failure in do_efuse_read/write if the return value of
meson_sm_read/write_efuse() is not the requested size.

Fixes: 52195ba5 ("ARM: amlogic: add sm efuse write support and cmd for read/write efuse")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20220804144138.33809-1-jbrunet@baylibre.com