tcpflood bugfix: plain tcp send error not properly reported

The error code when plain tcp sending failed was improperly returned,
resulting in no meaningful error message.

Note: tcpflood is a testbench tool, not part of production rsyslog.

tests/tcpflood.c

@@ -665,18 +665,18 @@ genMsg(char *buf, size_t maxBuf, size_t *pLenBuf, struct instdata *inst)
 
 
 static int
-sendPlainTCP(int socknum, char *buf, size_t lenBuf, int *ret_errno)
+sendPlainTCP(const int socknum, const char *const buf, const size_t lenBuf, int *const ret_errno)
 {
 	size_t lenSent;
-	int r, err;
+	int r;
 
 	lenSent = 0;
 	while(lenSent != lenBuf) {
 		r = send(sockArray[socknum], buf + lenSent, lenBuf - lenSent, 0);
 		if(r > 0) {
 			lenSent += r;
 		} else {
-			err = errno;
+			*ret_errno = errno;
 			goto finalize_it;
 		}
 	}