agfafocus: Fix [-Wshift-negative-value] compiler warning

backend/agfafocus.c

@@ -980,9 +980,9 @@ init_options (AgfaFocus_Scanner * s)
 
   static const SANE_Range percentage_range =
   {
-    -100 << SANE_FIXED_SCALE_SHIFT,	/* minimum */
-    100 << SANE_FIXED_SCALE_SHIFT,	/* maximum */
-    1 << SANE_FIXED_SCALE_SHIFT	/* quantization */
+    SANE_FIX(-100),	/* minimum */
+    SANE_FIX(100),	/* maximum */
+    SANE_FIX(1)         /* quantization */
   };
 
   static const SANE_Range sharpen_range =
@@ -991,9 +991,9 @@ init_options (AgfaFocus_Scanner * s)
   {0, 100, 0};
   static const SANE_Range attenuation_range =
   {
-    0 << SANE_FIXED_SCALE_SHIFT,	/* minimum */
-    100 << SANE_FIXED_SCALE_SHIFT,	/* maximum */
-    1 << SANE_FIXED_SCALE_SHIFT	        /* quantization */
+    SANE_FIX(0),	/* minimum */
+    SANE_FIX(100),	/* maximum */
+    SANE_FIX(1)	        /* quantization */
   };