reduce the amount of compilation warnings

src/miscfileformats.c

@@ -7895,6 +7895,8 @@ void Load_GRB(T_IO_Context * context)
   else
     bpp = 1;
 
+  GFX2_Log(GFX2_DEBUG, "HP48: %05X size=%u %ux%u\n", prologue, size, width, height);
+
   File_error = 0;
   Pre_load(context, width, height/bpp, file_size, FORMAT_GRB, PIXEL_SIMPLE, bpp);
   if (File_error == 0)

src/tests/mockloadsave.c

@@ -102,6 +102,8 @@ void Set_saving_layer(T_IO_Context *context, int layer)
 
 void Set_loading_layer(T_IO_Context *context, int layer)
 {
+  (void)context;
+  (void)layer;
   //printf("Set_loading_layer(%p, %d)\n", context, layer);
 }
 
@@ -112,6 +114,7 @@ void Set_image_mode(T_IO_Context *context, enum IMAGE_MODES mode)
 
 enum IMAGE_MODES Get_image_mode(T_IO_Context *context)
 {
+  (void)context;
   return -1;
 }
 

src/tests/testformats.c

@@ -214,7 +214,7 @@ int Test_Save(void)
 {
   T_IO_Context context;
   char path[256];
-  char tmpdir[256];
+  char tmpdir[40];
   int i;
   int ok = 0;
   T_GFX2_Surface * testpic256 = NULL;

src/tests/testmain.c

@@ -105,6 +105,8 @@ int main(int argc, char * * argv)
 {
   int i, r;
   int fail = 0;
+  (void)argc;
+  (void)argv;
 
   GFX2_verbosity_level = GFX2_DEBUG;
   init();