bitmap: Define a cleanup function for bitmaps

Add support for autopointers for bitmaps allocated with bitmap_alloc()
et al.

Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Acked-by: Yury Norov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Bartosz Golaszewski

include/linux/bitmap.h

@@ -6,6 +6,7 @@
 
 #include <linux/align.h>
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/errno.h>
 #include <linux/find.h>
 #include <linux/limits.h>
@@ -127,6 +128,8 @@ unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
 unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
 void bitmap_free(const unsigned long *bitmap);
 
+DEFINE_FREE(bitmap, unsigned long *, if (_T) bitmap_free(_T))
+
 /* Managed variants of the above. */
 unsigned long *devm_bitmap_alloc(struct device *dev,
 				 unsigned int nbits, gfp_t flags);