Fix double buffer not disabled for smaller devices.

Author: HiFiPhile

src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c

@@ -650,10 +650,11 @@ bool dcd_edpt_iso_alloc(uint8_t rhport, uint8_t ep_addr, uint16_t largest_packet
 
   /* Create a packet memory buffer area. Enable double buffering for devices with 2048 bytes PMA,
      for smaller devices double buffering occupy too much space. */
-  uint32_t pma_addr = dcd_pma_alloc(largest_packet_size, true);
 #if FSDEV_PMA_SIZE > 1024u
+  uint32_t pma_addr = dcd_pma_alloc(largest_packet_size, true);
   uint16_t pma_addr2 = pma_addr >> 16;
 #else
+  uint32_t pma_addr = dcd_pma_alloc(largest_packet_size, false);
   uint16_t pma_addr2 = pma_addr;
 #endif