wifi_scan_example: Indentation Fixes

- Trailing white spaces removed
- Re-formatted switch-case

Basic indentation fixes were done using tools/format.sh and switch-case
formatting was done manually (to identify different levels for "switch"
and "case")

Signed-off-by: Piyush Shah <piyush@espressif.com>

examples/wifi/scan/main/scan.c

@@ -65,7 +65,7 @@ static const char *TAG = "scan";
 
 static esp_err_t event_handler(void *ctx, system_event_t *event)
 {
-    switch(event->event_id) {
+    switch (event->event_id) {
         case SYSTEM_EVENT_STA_START:
             ESP_LOGI(TAG, "SYSTEM_EVENT_STA_START");
             ESP_ERROR_CHECK(esp_wifi_connect());