Bug 488955 - Fix linear gamma input tables, used in iCCP PNG testsuite images. r=joe

gfx/qcms/transform.c

@@ -79,7 +79,7 @@ void compute_curve_gamma_table_type0(float gamma_table[256])
 {
 	unsigned int i;
 	for (i = 0; i < 256; i++) {
-		gamma_table[i] = i;
+		gamma_table[i] = i/255.;
 	}
 }