lib/decompress: use designated initializers for struct compress_format

Switch 'compressed_formats[]' to the more modern and flexible designated
initializers.  This improves readability and allows struct fields to be
reordered.  Also use a more concise sentinel marker.

Remove the curly braces around the for loop while we're at it.

No functional changes intended.

Link: https://lkml.kernel.org/r/20250910232350.1308206-2-thorsten.blum@linux.dev
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: toblux

lib/decompress.c

@@ -49,15 +49,15 @@ struct compress_format {
 };
 
 static const struct compress_format compressed_formats[] __initconst = {
-	{ {0x1f, 0x8b}, "gzip", gunzip },
-	{ {0x1f, 0x9e}, "gzip", gunzip },
-	{ {0x42, 0x5a}, "bzip2", bunzip2 },
-	{ {0x5d, 0x00}, "lzma", unlzma },
-	{ {0xfd, 0x37}, "xz", unxz },
-	{ {0x89, 0x4c}, "lzo", unlzo },
-	{ {0x02, 0x21}, "lz4", unlz4 },
-	{ {0x28, 0xb5}, "zstd", unzstd },
-	{ {0, 0}, NULL, NULL }
+	{ .magic = {0x1f, 0x8b}, .name = "gzip", .decompressor = gunzip },
+	{ .magic = {0x1f, 0x9e}, .name = "gzip", .decompressor = gunzip },
+	{ .magic = {0x42, 0x5a}, .name = "bzip2", .decompressor = bunzip2 },
+	{ .magic = {0x5d, 0x00}, .name = "lzma", .decompressor = unlzma },
+	{ .magic = {0xfd, 0x37}, .name = "xz", .decompressor = unxz },
+	{ .magic = {0x89, 0x4c}, .name = "lzo", .decompressor = unlzo },
+	{ .magic = {0x02, 0x21}, .name = "lz4", .decompressor = unlz4 },
+	{ .magic = {0x28, 0xb5}, .name = "zstd", .decompressor = unzstd },
+	{ /* sentinel */ }
 };
 
 decompress_fn __init decompress_method(const unsigned char *inbuf, long len,
@@ -73,11 +73,10 @@ decompress_fn __init decompress_method(const unsigned char *inbuf, long len,
 
 	pr_debug("Compressed data magic: %#.2x %#.2x\n", inbuf[0], inbuf[1]);
 
-	for (cf = compressed_formats; cf->name; cf++) {
+	for (cf = compressed_formats; cf->name; cf++)
 		if (!memcmp(inbuf, cf->magic, 2))
 			break;
 
-	}
 	if (name)
 		*name = cf->name;
 	return cf->decompressor;