devres: constify p in devm_kfree()

Make devm_kfree() signature uniform with that of kfree(). To avoid
compiler warnings: cast p to (void *) when calling devres_destroy().

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/device.h b/include/linux/device.h
index 767cf19..c2022c1 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -694,7 +694,7 @@
 {
 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
 }
-extern void devm_kfree(struct device *dev, void *p);
+extern void devm_kfree(struct device *dev, const void *p);
 extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
 extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
 			  gfp_t gfp);