Simplify the use of free

Quote from man pages:
   The free() function deallocates the memory allocation pointed to by
   ptr. If ptr is a NULL pointer, no operation is performed.

Thus, no extra if statement is required before the invocation of free.

Author: jserv

src/draw.c

@@ -421,8 +421,7 @@ static twin_xform_t *twin_pixmap_init_xform(twin_pixmap_t *pixmap,
 
 static void twin_pixmap_free_xform(twin_xform_t *xform)
 {
-    if (xform)
-        free(xform);
+    free(xform);
 }
 
 #define FX(x) twin_int_to_fixed(x)

src/path.c

@@ -450,10 +450,8 @@ twin_path_t *twin_path_create(void)
 
 void twin_path_destroy(twin_path_t *path)
 {
-    if (path->points)
-        free(path->points);
-    if (path->sublen)
-        free(path->sublen);
+    free(path->points);
+    free(path->sublen);
     free(path);
 }
 

src/window.c

@@ -76,8 +76,7 @@ void twin_window_destroy(twin_window_t *window)
 {
     twin_window_hide(window);
     twin_pixmap_destroy(window->pixmap);
-    if (window->name)
-        free(window->name);
+    free(window->name);
     free(window);
 }
 
@@ -149,8 +148,7 @@ void twin_window_style_size(twin_window_style_t style, twin_rect_t *size)
 
 void twin_window_set_name(twin_window_t *window, const char *name)
 {
-    if (window->name)
-        free(window->name);
+    free(window->name);
     window->name = malloc(strlen(name) + 1);
     if (window->name)
         strcpy(window->name, name);