style: samples: comply with MISRA C:2012 Rule 15.6

Add missing braces to comply with MISRA C:2012 Rule 15.6 and
also following Zephyr's style guideline.

Signed-off-by: Pisit Sawangvonganan <[email protected]>

Author: ndrs-pst

samples/bluetooth/tmap_peripheral/src/main.c

@@ -298,8 +298,9 @@ int main(void)
 	if (peer_is_ums) {
 		/* Play media with MCP */
 		err = mcp_send_cmd(BT_MCS_OPC_PLAY);
-		if (err != 0)
+		if (err != 0) {
 			printk("Error sending media play command!\n");
+		}
 
 		/* Start timer to send media pause command */
 		k_work_schedule(&media_pause_set_work, K_MSEC(2000));

samples/drivers/virtualization/ivshmem/doorbell/src/ivshmem.c

@@ -197,8 +197,9 @@ static void ivshmem_sample_doorbell(void)
 	int ret;
 
 	ret = setup_ivshmem(true);
-	if (ret < 0)
+	if (ret < 0) {
 		return;
+	}
 	ivshmem_event_loop(&shmem_ctx);
 	/*
 	 * if ivshmem_event_loop() returns, it means the function failed

samples/shields/x_nucleo_iks01a3/standard/src/main.c

@@ -341,8 +341,9 @@ int main(void)
 	stts751_config(stts751);
 	lis2dw12_config(lis2dw12);
 	lsm6dso_config(lsm6dso);
-	if (lis2de12_on_dil24)
+	if (lis2de12_on_dil24) {
 		lis2de12_config(lis2de12);
+	}
 
 	while (1) {
 		/* Get sensor samples */

samples/subsys/debug/debugmon/src/main.c

@@ -51,8 +51,9 @@ void z_arm_debug_monitor(void)
 	printk("Entered debug monitor interrupt\n");
 
 	/* Spin in breakpoint. Other, higher-priority interrupts will continue to execute */
-	while (true)
+	while (true) {
 		;
+	}
 }
 
 int main(void)