soc: qcom: qmi_encdec: Restrict string length in decode

The QMI TLV value for strings in a lot of qmi element info structures
account for null terminated strings with MAX_LEN + 1. If a string is
actually MAX_LEN + 1 length, this will cause an out of bounds access
when the NULL character is appended in decoding.

Fixes: 9b8a11e8

 ("soc: qcom: Introduce QMI encoder/decoder")
Cc: stable@vger.kernel.org
Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
Link: https://lore.kernel.org/r/20230801064712.3590128-1-quic_ipkumar@quicinc.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>