bus: fsl-mc: fsl-mc-allocator: Initialize mc_bus_dev before use

Fixes a clang compiler warning:

>> drivers/bus/fsl-mc/fsl-mc-allocator.c:108:12: warning: variable 'mc_bus_dev' is uninitialized when used here [-Wuninitialized]
                   dev_err(&mc_bus_dev->dev, "resource mismatch\n");

Fixes: b3134039 ("bus: fsl-mc: fsl-mc-allocator: Improve error reporting")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306021936.OktTcMAT-lkp@intel.com/


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Li Yang <leoyang.li@nxp.com>