staging: erofs: fix undefined LZ4_decompress_safe_partial()

It needs an explicit LZ4 library dependency
if lz4 compression is enabled, found by kbuild randconfig.
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 05f9d4a0 ("staging: erofs: use the new LZ4_decompress_safe_partial()")
Signed-off-by: Gao Xiang <hsiangkao@aol.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/erofs/Kconfig

@@ -90,8 +90,9 @@ config EROFS_FS_IO_MAX_RETRIES
 config EROFS_FS_ZIP
 	bool "EROFS Data Compresssion Support"
 	depends on EROFS_FS
+	select LZ4_DECOMPRESS
 	help
-	  Currently we support VLE Compression only.
+	  Currently we support LZ4 VLE Compression only.
 	  Play at your own risk.
 
 	  If you don't want to use compression feature, say N.