Fix a leak with a free before return.

Reference: /n/sources/patch/applied/ndbipinfo-leak
Date: Thu Sep  7 15:04:48 CES 2006
Signed-off-by: gabidiaz@gmail.com

--- /sys/src/libndb/ndbipinfo.c	Thu Sep  7 15:01:40 2006
+++ /sys/src/libndb/ndbipinfo.c	Thu Sep  7 15:01:37 2006
@@ -181,8 +181,10 @@
 	ipstr = ndbgetvalue(db, &s, attr, val, "ip", &nt);
 	if(ipstr == nil){
 		/* none found, make one up */
-		if(strcmp(attr, "ip") != 0)
-			return nil;
+		if(strcmp(attr, "ip") != 0) {
+			ndbfree(f);
+			return nil;	
+		}
 		t = ndbnew("ip", val);
 		t->line = t;
 		t->entry = nil;