bpf: Correct the comment for BTF kind bitfield

The commit 8fd886911a ("bpf: Add BTF_KIND_FLOAT to uapi") has extended
the BTF kind bitfield from 4 to 5 bits, correct the comment.

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220403115327.205964-1-haiyue.wang@intel.com

include/uapi/linux/btf.h

@@ -33,8 +33,8 @@ struct btf_type {
 	/* "info" bits arrangement
 	 * bits  0-15: vlen (e.g. # of struct's members)
 	 * bits 16-23: unused
-	 * bits 24-27: kind (e.g. int, ptr, array...etc)
-	 * bits 28-30: unused
+	 * bits 24-28: kind (e.g. int, ptr, array...etc)
+	 * bits 29-30: unused
 	 * bit     31: kind_flag, currently used by
 	 *             struct, union and fwd
 	 */

tools/include/uapi/linux/btf.h

@@ -33,8 +33,8 @@ struct btf_type {
 	/* "info" bits arrangement
 	 * bits  0-15: vlen (e.g. # of struct's members)
 	 * bits 16-23: unused
-	 * bits 24-27: kind (e.g. int, ptr, array...etc)
-	 * bits 28-30: unused
+	 * bits 24-28: kind (e.g. int, ptr, array...etc)
+	 * bits 29-30: unused
 	 * bit     31: kind_flag, currently used by
 	 *             struct, union and fwd
 	 */