cairo,svg: convert "while" to "for" (code simplification)

Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
diff --git a/cairo.c b/cairo.c
index 881b144..23dd628 100644
--- a/cairo.c
+++ b/cairo.c
@@ -10,7 +10,6 @@
 	int width  = pes->max_x - pes->min_x, outw;
 	int height = pes->max_y - pes->min_y, outh;
 	double scale = 1.0;
-	struct pes_block *block;
 	cairo_surface_t *surface;
 	cairo_t *cr;
 
@@ -24,8 +23,7 @@
 	surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, outw+1, outh+1);
 	cr = cairo_create (surface);
 
-	block = pes->blocks;
-	while (block) {
+	for (struct pes_block *block = pes->blocks; block; block = block->next) {
 		struct color *c = block->color;
 		struct stitch *stitch = block->stitch;
 		int i;
@@ -42,8 +40,6 @@
 		cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND);
 		cairo_set_line_join(cr, CAIRO_LINE_JOIN_ROUND);
 		cairo_stroke(cr);
-
-		block = block->next;
 	}
 	cairo_surface_write_to_png(surface, filename);
 }
diff --git a/svg.c b/svg.c
index c792716..1237a64 100644
--- a/svg.c
+++ b/svg.c
@@ -3,8 +3,6 @@
 
 void output_svg(struct pes *pes)
 {
-	struct pes_block *block = pes->blocks;
-
 	printf("<?xml version=\"1.0\"?>\n");
 	printf("<svg xmlns=\"http://www.w3.org/2000/svg\" "
 		"xlink=\"http://www.w3.org/1999/xlink\" "
@@ -15,7 +13,7 @@
 		pes->max_x - pes->min_x,
 		pes->max_y - pes->min_y);
 
-	while (block) {
+	for (struct pes_block *block = pes->blocks; block; block = block->next) {
 		int i;
 		printf("<path stroke=\"#%02x%02x%02x\" fill=\"none\" d=\"M %d %d",
 			block->color->r,
@@ -28,8 +26,6 @@
 				block->stitch[i].x - pes->min_x,
 				block->stitch[i].y - pes->min_y);
 		printf("\"/>");
-
-		block = block->next;
 	}
 	printf("</svg>\n");
 }