bus: fsl-mc: Fix test for end of loop

The "desc" pointer can't possibly be NULL here.  If we can't find the
correct "desc" then tt points to the last element of the
fsl_mc_accepted_cmds[] array.  Fix this by testing if
"i == FSL_MC_NUM_ACCEPTED_CMDS" instead.

Fixes: 2cf1e703 ("bus: fsl-mc: add fsl-mc userspace support")
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210208170949.3070898-2-ciorneiioana@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/fsl-mc/fsl-mc-uapi.c

@@ -338,7 +338,7 @@ static int fsl_mc_command_check(struct fsl_mc_device *mc_dev,
 		if ((cmdid & desc->cmdid_mask) == desc->cmdid_value)
 			break;
 	}
-	if (!desc) {
+	if (i == FSL_MC_NUM_ACCEPTED_CMDS) {
 		dev_err(&mc_dev->dev, "MC command 0x%04x: cmdid not accepted\n", cmdid);
 		return -EACCES;
 	}