esp_http_client/esp_https_ota: Removed errno checks

- Returned -ESP_ERR_HTTP_EAGAIN for timeout errors from
  esp_http_client whenever tcp transport layer returns
  connection timeout
- Removed redundant conditional statements as required

Co-authored-by: Shubham Kulkarni <shubham.kulkarni@espressif.com>

components/esp_http_client/include/esp_http_client.h

@@ -427,6 +427,7 @@ int esp_http_client_write(esp_http_client_handle_t client, const char *buffer, i
  * @return
  *     - (0) if stream doesn't contain content-length header, or chunked encoding (checked by `esp_http_client_is_chunked` response)
  *     - (-1: ESP_FAIL) if any errors
+ *     - (-ESP_ERR_HTTP_EAGAIN = -0x7007) if call is timed-out before any data was ready
  *     - Download data length defined by content-length header
  */
 int64_t esp_http_client_fetch_headers(esp_http_client_handle_t client);
@@ -451,6 +452,8 @@ bool esp_http_client_is_chunked_response(esp_http_client_handle_t client);
  * @return
  *     - (-1) if any errors
  *     - Length of data was read
+ *
+ * @note  (-ESP_ERR_HTTP_EAGAIN = -0x7007) is returned when call is timed-out before any data was ready
  */
 int esp_http_client_read(esp_http_client_handle_t client, char *buffer, int len);