soc: fsl: dpaa2-console: free buffer before returning from dpaa2_console_read

Free the kbuf buffer before returning from the dpaa2_console_read()
function. The variable no longer goes out of scope, leaking the storage
it points to.

Fixes: c93349d8 ("soc: fsl: add DPAA2 console support")
Signed-off-by: NRobert-Ionut Alexa <robert-ionut.alexa@nxp.com>
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NLi Yang <leoyang.li@nxp.com>

drivers/soc/fsl/dpaa2-console.c

@@ -231,6 +231,7 @@ static ssize_t dpaa2_console_read(struct file *fp, char __user *buf,
 	cd->cur_ptr += bytes;
 	written += bytes;
 
+	kfree(kbuf);
 	return written;
 
 err_free_buf: