isdn: eicon: Return on error

When diva_strace_read_uint returns an error, return even from
process_idi_event, because l2_state is uninitialized.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Acked-by: NArmin Schindler <armin@melware.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/isdn/hardware/eicon/maintidi.c

@@ -959,8 +959,9 @@ static int process_idi_event (diva_strace_context_t* pLib,
 	}
 	if (!strncmp("State\\Layer2 No1", path, pVar->path_length)) {
 		char* tmp = &pLib->lines[0].pInterface->Layer2[0];
-    dword l2_state;
-    diva_strace_read_uint (pVar, &l2_state);
+		dword l2_state;
+		if (diva_strace_read_uint(pVar, &l2_state))
+			return -1;
 
 		switch (l2_state) {
 			case 0: