Philippe 25/05/2018: IO: small correction for COVERxxx comments

src/MNH/write_surf_mnh.f90

@@ -662,7 +662,6 @@ IF (.NOT. GCOVER_PACKED) THEN
   ICOVER=0
   TZFIELD%CSTDNAME   = ''
   TZFIELD%CUNITS     = ''
-  TZFIELD%CCOMMENT   = TRIM(HCOMMENT)
   TZFIELD%NGRID      = 4
   TZFIELD%NTYPE      = TYPEREAL
   TZFIELD%NDIMS      = 2
@@ -672,6 +671,7 @@ IF (.NOT. GCOVER_PACKED) THEN
     TZFIELD%CMNHNAME   = TRIM(YREC)
     TZFIELD%CLONGNAME  = TRIM(YREC)
     TZFIELD%CDIR       = YDIR
+    TZFIELD%CCOMMENT   = 'X_Y_'//TRIM(YREC)
     IF (OFLAG(JL2)) THEN
       ICOVER=ICOVER+1
       CALL IO_WRITE_FIELD(TFILE_SURFEX,TZFIELD,ZWORK3D(1+NHALO:IIU-NHALO,1+NHALO:IJU-NHALO,ICOVER),KRESP)