Dataflash: correct the multiplier factor of POS *Alt data

libraries/DataFlash/LogStructure.h

@@ -1250,7 +1250,7 @@ Format characters in the format string for binary log messages
     { LOG_AHR2_MSG, sizeof(log_AHRS), \
       "AHR2","QccCfLLffff","TimeUS,Roll,Pitch,Yaw,Alt,Lat,Lng,Q1,Q2,Q3,Q4","sddhmDU????", "FBBBBGG????" }, \
     { LOG_POS_MSG, sizeof(log_POS), \
-      "POS","QLLfff","TimeUS,Lat,Lng,Alt,RelHomeAlt,RelOriginAlt", "sDUmmm", "FGGBBB" }, \
+      "POS","QLLfff","TimeUS,Lat,Lng,Alt,RelHomeAlt,RelOriginAlt", "sDUmmm", "FGG000" }, \
     { LOG_SIMSTATE_MSG, sizeof(log_AHRS), \
       "SIM","QccCfLLffff","TimeUS,Roll,Pitch,Yaw,Alt,Lat,Lng,Q1,Q2,Q3,Q4", "sddhmDU????", "FBBB0GG????" }, \
     { LOG_NKF1_MSG, sizeof(log_EKF1), \