[PATCH] rpm2cpio: print name of unknown compression method

Commit f13f68288 (rpm2cpio: extract cpio even if compression is
not known) added an error message if the compression method was
unknown.  When support for lzma was disabled this resulted in a
null pointer being passed to bb_error_msg().

The call to rpm_getstr0() to fetch the name of the compression
method shouldn't depend on lzma being supported.

This doesn't affect the size of a default build.  In a build with
lzma disabled:

function                                             old     new   delta
rpm2cpio_main                                        110     121     +11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 11/0)               Total: 11 bytes

Signed-off-by: Ron Yorston <[email protected]>
---
 archival/rpm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/archival/rpm.c b/archival/rpm.c
index 95a8c79b6..899587751 100644
--- a/archival/rpm.c
+++ b/archival/rpm.c
@@ -533,9 +533,9 @@ int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
 	//	/* We need to know whether child (gzip/bzip/etc) exits abnormally */
 	//	signal(SIGCHLD, check_errors_in_children);
 
-	str = NULL;
+	str = rpm_getstr0(TAG_PAYLOADCOMPRESSOR);
 	if (ENABLE_FEATURE_SEAMLESS_LZMA
-	 && (str = rpm_getstr0(TAG_PAYLOADCOMPRESSOR)) != NULL
+	 && str != NULL
 	 && strcmp(str, "lzma") == 0
 	) {
 		// lzma compression can't be detected
-- 
2.53.0