staging: rtl8192e: convert else if sequence to switch

Convert a sequence of else if statements that all check the same
variable to a single switch statement. With a switch statement it is
easier to see what is going on. Additionally this clears a checkpatch
warning.

WARNING: braces {} are not necessary for any arm of this statement
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/20230619150953.22484-3-straube.linux@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192e/rtllib_softmac.c

@@ -2830,15 +2830,19 @@ void rtllib_start_protocol(struct rtllib_device *ieee)
 	 * attempts does not fail just because the user provide the essid
 	 * and the nic is still checking for the AP MAC ??
 	 */
-	if (ieee->iw_mode == IW_MODE_INFRA) {
+	switch (ieee->iw_mode) {
+	case IW_MODE_INFRA:
 		rtllib_start_bss(ieee);
-	} else if (ieee->iw_mode == IW_MODE_ADHOC) {
+		break;
+	case IW_MODE_ADHOC:
 		rtllib_start_ibss(ieee);
-
-	} else if (ieee->iw_mode == IW_MODE_MASTER) {
+		break;
+	case IW_MODE_MASTER:
 		rtllib_start_master_bss(ieee);
-	} else if (ieee->iw_mode == IW_MODE_MONITOR) {
+		break;
+	case IW_MODE_MONITOR:
 		rtllib_start_monitor_mode(ieee);
+		break;
 	}
 }