Repair a file handle leak in wsprd

lib/wsprd/wsprd.c

@@ -677,6 +677,7 @@ unsigned long writec2file(char *c2filename, int trmin, double freq
     }
     nwrite = fwrite(buffer, sizeof(float), 2*45000, fp);
     free(buffer);
+    fclose(fp);
     if( nwrite == 2*45000 ) {
         return nwrite;
     } else {