devip: handle malloc errors, fix queue leaks

Fsprotocone():

qopen() and qbypass() can fail and return nil, so make sure
the connection was not partially created by checking if read
and write queues have been setup by the protocol create hanler.
on error, free any resources of the partial connection and
error out.

netlogopen(): check malloc() error.

sys/src/9/ip/devip.c

@@ -1286,20 +1286,32 @@ retry:
 			c = malloc(sizeof(Conv));
 			if(c == nil)
 				error(Enomem);
-			qlock(c);
+			if(waserror()){
+				qfree(c->rq);
+				qfree(c->wq);
+				qfree(c->eq);
+				qfree(c->sq);
+				free(c->ptcl);
+				free(c);
+				nexterror();
+			}
 			c->p = p;
 			c->x = pp - p->conv;
 			if(p->ptclsize != 0){
 				c->ptcl = malloc(p->ptclsize);
-				if(c->ptcl == nil) {
-					free(c);
+				if(c->ptcl == nil)
 					error(Enomem);
 			}
-			}
+			c->eq = qopen(1024, Qmsg, 0, 0);
+			if(c->eq == nil)
+				error(Enomem);
+			(*p->create)(c);
+			if(c->rq == nil || c->wq == nil)
+				error(Enomem);
+			poperror();
+			qlock(c);
 			*pp = c;
 			p->ac++;
-			c->eq = qopen(1024, Qmsg, 0, 0);
-			(*p->create)(c);
 			break;
 		}
 		if(canqlock(c)){

sys/src/9/ip/ipifc.c

@@ -316,8 +316,10 @@ ipifccreate(Conv *c)
 	Ipifc *ifc;
 
 	c->rq = qopen(QMAX, 0, 0, 0);
-	c->sq = qopen(QMAX, 0, 0, 0);
 	c->wq = qopen(QMAX, Qkick, ipifckick, c);
+	c->sq = qopen(QMAX, 0, 0, 0);
+	if(c->rq == nil || c->wq == nil || c->sq == nil)
+		error(Enomem);
 	ifc = (Ipifc*)c->ptcl;
 	ifc->conv = c;
 	ifc->unbinding = 0;

sys/src/9/ip/netlog.c

@@ -85,8 +85,11 @@ netlogopen(Fs *f)
 		nexterror();
 	}
 	if(f->alog->opens == 0){
-		if(f->alog->buf == nil)
+		if(f->alog->buf == nil){
 			f->alog->buf = malloc(Nlog);
+			if(f->alog->buf == nil)
+				error(Enomem);
+		}
 		f->alog->rptr = f->alog->buf;
 		f->alog->end = f->alog->buf + Nlog;
 	}