[PATCH] kbuild: use lz4 instead of lz4c

[Justin Bronder <jsbronder@cold-front.org>]

lz4c has been considered deprecated by upstream since at least 2018 [1]
and has been disabled by default recently [2].  openSUSE Tumbleweed is
no longer packaging the deprecated version and others will likely
follow.

Going back as far as Ubuntu 16.04/Fedora 25, both lz4 and lz4c are
installed as part of the same package and both accept -9 to enable high
compression so switching should be safe.

1. https://github.com/lz4/lz4/pull/553
2. https://github.com/lz4/lz4/pull/1479

Signed-off-by: Justin Bronder <jsbronder@cold-front.org>
---
 Makefile             | 2 +-
 scripts/Makefile.lib | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 68a8faff2543..ded07aca0d2a 100644
--- a/Makefile
+++ b/Makefile
@@ -508,7 +508,7 @@ KGZIP		= gzip
 KBZIP2		= bzip2
 KLZOP		= lzop
 LZMA		= lzma
-LZ4		= lz4c
+LZ4		= lz4
 XZ		= xz
 ZSTD		= zstd
 
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 01a9f567d5af..b73950bfee34 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -371,10 +371,10 @@ quiet_cmd_lzo_with_size = LZO     $@
       cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
 
 quiet_cmd_lz4 = LZ4     $@
-      cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@
+      cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -9 stdin stdout > $@
 
 quiet_cmd_lz4_with_size = LZ4     $@
-      cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
+      cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -9 stdin stdout; \
                   $(size_append); } > $@
 
 # U-Boot mkimage
-- 
2.47.0