Decompressors: get rid of set_error_fn() macro

set_error_fn() has become a useless complication after c1e7c3ae59
("bzip2/lzma/gzip: pre-boot malloc doesn't return NULL on failure") fixed
the use of error() in malloc().  Only decompress_unlzma.c had some use for
it and that was easy to change too.

This also gets rid of the static function pointer "error", which
should have been marked as __initdata.

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/decompress_inflate.c b/lib/decompress_inflate.c
index 1eea07e..9a7f5df 100644
--- a/lib/decompress_inflate.c
+++ b/lib/decompress_inflate.c
@@ -38,13 +38,12 @@
 		       int(*flush)(void*, unsigned int),
 		       unsigned char *out_buf,
 		       int *pos,
-		       void(*error_fn)(char *x)) {
+		       void(*error)(char *x)) {
 	u8 *zbuf;
 	struct z_stream_s *strm;
 	int rc;
 	size_t out_len;
 
-	set_error_fn(error_fn);
 	rc = -1;
 	if (flush) {
 		out_len = 0x8000; /* 32 K */