device_tree: Constify compat in qemu_fdt_node_path()

Make compat in qemu_fdt_node_path() const char *.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20200423121114.4274-3-edgar.iglesias@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

device_tree.c

@@ -291,7 +291,7 @@ char **qemu_fdt_node_unit_path(void *fdt, const char *name, Error **errp)
     return path_array;
 }
 
-char **qemu_fdt_node_path(void *fdt, const char *name, char *compat,
+char **qemu_fdt_node_path(void *fdt, const char *name, const char *compat,
                           Error **errp)
 {
     int offset, len, ret;

include/sysemu/device_tree.h

@@ -43,7 +43,7 @@ void *load_device_tree_from_sysfs(void);
  * @name may be NULL to wildcard names and only match compatibility
  * strings.
  */
-char **qemu_fdt_node_path(void *fdt, const char *name, char *compat,
+char **qemu_fdt_node_path(void *fdt, const char *name, const char *compat,
                           Error **errp);
 
 /**