drivers/net: process the result of hdlc_open() and add call of hdlc_close() in uhdlc_close()

Process the result of hdlc_open() and call uhdlc_close()
in case of an error. It is necessary to pass the error
code up the control flow, similar to a possible
error in request_irq().
Also add a hdlc_close() call to the uhdlc_close()
because the comment to hdlc_close() says it must be called
by the hardware driver when the HDLC device is being closed

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: c19b6d24 ("drivers/net: support hdlc function for QE-UCC")
Signed-off-by: Alexandra Diupina <adiupina@astralinux.ru>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>