Add parantheses to assignment in condition (#1274)

Fixes -Wparentheses compiler warnings.

lib/dspf/cube_io.c

@@ -171,7 +171,7 @@ int read_cube(Cube_data * Cube, file_info * headfax)
 	    break;
 	}
 
-	for (i = 0; ret = fread(fptr + i, 1, 10240, fp); i += ret) ;
+	for (i = 0; (ret = fread(fptr + i, 1, 10240, fp)); i += ret) ;
     }
 
     if (zeros_left) {

raster/r.in.gridatb/file_io.c

@@ -28,7 +28,7 @@ void rdwr_gridatb(void)
     cellhd.format = -1;
     cellhd.compressed = 1;
 
-    if (retval = adjcellhd(&cellhd)) {
+    if ((retval = adjcellhd(&cellhd))) {
 	fclose(fp);
 	switch (retval) {
 	case 1: