i3c: master: adi: Fix error propagation for CCCs

i3c: master: adi: Fix error propagation for CCCs

adi_i3c_master_send_ccc_cmd() always returned 0, ignoring the transfer
result populated in the completion path. As a consequence, CCC command
errors were silently dropped, including the default -ETIMEDOUT and
later overwritten by adi_i3c_master_end_xfer_locked().

Fix this by returning xfer->ret so that callers correctly receive any
transfer error codes.

Fixes: a79ac2cdc91d ("i3c: master: Add driver for Analog Devices I3C Controller IP")
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jorge Marques <jorge.marques@analog.com>
Link: https://patch.msgid.link/20260323-ad4062-positive-error-fix-v3-5-30bdc68004be@analog.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>