tools: Fix handle leak in rfcomm

Some branches of execution can make handle (socket) leakage.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.
diff --git a/tools/rfcomm.c b/tools/rfcomm.c
index cd520aa..e013ff5 100644
--- a/tools/rfcomm.c
+++ b/tools/rfcomm.c
@@ -298,6 +298,7 @@
 
 		if (setsockopt(sk, SOL_SOCKET, SO_LINGER, &l, sizeof(l)) < 0) {
 			perror("Can't set linger option");
+			close(sk);
 			return;
 		}
 	}
@@ -466,6 +467,7 @@
 	if (getsockname(nsk, (struct sockaddr *)&laddr, &alen) < 0) {
 		perror("Can't get RFCOMM socket name");
 		close(nsk);
+		close(sk);
 		return;
 	}
 
@@ -475,6 +477,7 @@
 		if (setsockopt(nsk, SOL_SOCKET, SO_LINGER, &l, sizeof(l)) < 0) {
 			perror("Can't set linger option");
 			close(nsk);
+			close(sk);
 			return;
 		}
 	}
@@ -490,6 +493,7 @@
 	dev = ioctl(nsk, RFCOMMCREATEDEV, &req);
 	if (dev < 0) {
 		perror("Can't create RFCOMM TTY");
+		close(nsk);
 		close(sk);
 		return;
 	}