Fix the data format used in apps/examples/adc

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4193 42af7a65-404d-4744-a932-0658087f49c3

include/nuttx/analog/adc.h

@@ -78,7 +78,7 @@ struct adc_msg_s
 {
   uint8_t      am_channel;               /* The 8-bit ADC Channel */
   int32_t      am_data;                  /* ADC convert result (4 bytes) */
-}__attribute__((__packed__));
+} __attribute__((__packed__));
 
 struct adc_fifo_s
 {