Fix resource and memory leaks in examples as reported by cppcheck

Thanks to Ettl Martin for the report and patch. This fixes #132

example/scp_write.c

@@ -197,6 +197,8 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
+    if (local)
+        fclose(local);
     fprintf(stderr, "all done\n");
     return 0;
 }

example/sftp_RW_nonblock.c

@@ -283,6 +283,8 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
+    if (tempstorage)
+        fclose(tempstorage);
     printf("all done\n");
     return 0;
 }

example/sftp_write.c

@@ -184,12 +184,10 @@ int main(int argc, char *argv[])
         } while (rc > 0);
     } while (1);
 
-    fclose(local);
     libssh2_sftp_close(sftp_handle);
     libssh2_sftp_shutdown(sftp_session);
 
- shutdown:
-
+shutdown:
     libssh2_session_disconnect(session,
                                "Normal Shutdown, Thank you for playing");
     libssh2_session_free(session);
@@ -199,6 +197,8 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
-printf("all done\n");
+    if (local)
+        fclose(local);
+    printf("all done\n");
     return 0;
 }

example/x11.c

@@ -121,11 +121,16 @@ static void x11_callback(LIBSSH2_SESSION *session, LIBSSH2_CHANNEL *channel,
             /* Connect to the local unix domain */
             ptr = strrchr(display, ':');
             temp_buff = (char *) calloc(strlen(ptr+1), sizeof(char));
+            if (!temp_buff) {
+                perror("calloc");
+                return;
+            }
             memcpy(temp_buff, ptr+1, strlen(ptr+1));
             display_port = atoi(temp_buff);
+            free(temp_buff);
 
-            sock = socket(AF_UNIX,SOCK_STREAM, 0);
-            if (sock <0)
+            sock = socket(AF_UNIX, SOCK_STREAM, 0);
+            if (sock < 0)
                 return;
             memset(&addr, 0, sizeof(addr));
             addr.sun_family = AF_UNIX;