config-parser: use zalloc()

While the code looks fine, clang 7 memory sanitizer complains about
things like:

==26052==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x7f4f4d003327 in weston_config_get_section /home/pq/build/weston-clang/../../git/weston/shared/config-parser.c:141:2
    #1 0x7f4f4cfce11a in wet_main /home/pq/build/weston-clang/../../git/weston/compositor/main.c:3266:12

==26683==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x7f09ebd638e2 in config_section_get_entry /home/pq/build/weston-clang/../../git/weston/shared/config-parser.c:125:2
    #1 0x7f09ebd661c4 in weston_config_section_get_bool /home/pq/build/weston-clang/../../git/weston/shared/config-parser.c:310:10
    #2 0x7f09ebd2e1e5 in wet_main /home/pq/build/weston-clang/../../git/weston/compositor/main.c:3269:3

In all cases, the errors point to wl_list_for_each().

Making these allocations use zalloc() avoids these errors. Since using
zalloc() is a good habit in any case, I didn't dig deeper.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

shared/config-parser.c

@@ -39,6 +39,7 @@
 #include <errno.h>
 
 #include <wayland-util.h>
+#include <libweston/zalloc.h>
 #include <libweston/config-parser.h>
 #include "helpers.h"
 #include "string-helpers.h"
@@ -344,7 +345,7 @@ config_add_section(struct weston_config *config, const char *name)
 {
 	struct weston_config_section *section;
 
-	section = malloc(sizeof *section);
+	section = zalloc(sizeof *section);
 	if (section == NULL)
 		return NULL;
 
@@ -366,7 +367,7 @@ section_add_entry(struct weston_config_section *section,
 {
 	struct weston_config_entry *entry;
 
-	entry = malloc(sizeof *entry);
+	entry = zalloc(sizeof *entry);
 	if (entry == NULL)
 		return NULL;
 
@@ -399,7 +400,7 @@ weston_config_parse(const char *name)
 	struct weston_config_section *section = NULL;
 	int i, fd;
 
-	config = malloc(sizeof *config);
+	config = zalloc(sizeof *config);
 	if (config == NULL)
 		return NULL;