fix msc example with out of bound lba (due to compliant test)

examples/device/dynamic_configuration/src/msc_disk.c

@@ -178,6 +178,9 @@ int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buff
 {
   (void) lun;
 
+  // out of ramdisk
+  if ( lba >= DISK_BLOCK_NUM ) return -1;
+
   uint8_t const* addr = msc_disk[lba] + offset;
   memcpy(buffer, addr, bufsize);
 
@@ -190,6 +193,9 @@ int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t*
 {
   (void) lun;
 
+  // out of ramdisk
+  if ( lba >= DISK_BLOCK_NUM ) return -1;
+
 #ifndef CFG_EXAMPLE_MSC_READONLY
   uint8_t* addr = msc_disk[lba] + offset;
   memcpy(addr, buffer, bufsize);