libunarchive: fix build failure with !FEATURE_TAR_UNAME_GNAME

We can't use C if(...) with ENABLE_FEATURE_TAR_UNAME_GNAME because it
relies on conditional members in the file_header_t structure:

archival/libunarchive/data_extract_all.c: In function ‘data_extract_all’:
archival/libunarchive/data_extract_all.c:123: error: ‘file_header_t’ has no member named ‘uname’
archival/libunarchive/data_extract_all.c:124: error: ‘file_header_t’ has no member named ‘uname’
archival/libunarchive/data_extract_all.c:127: error: ‘file_header_t’ has no member named ‘gname’
archival/libunarchive/data_extract_all.c:128: error: ‘file_header_t’ has no member named ‘gname’
make[1]: *** [archival/libunarchive/data_extract_all.o] Error 1

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/archival/libunarchive/data_extract_all.c b/archival/libunarchive/data_extract_all.c
index a2dfcb9..444770d 100644
--- a/archival/libunarchive/data_extract_all.c
+++ b/archival/libunarchive/data_extract_all.c
@@ -114,9 +114,8 @@
 	}
 
 	if (!(archive_handle->ah_flags & ARCHIVE_NOPRESERVE_OWN)) {
-		if (ENABLE_FEATURE_TAR_UNAME_GNAME
-		 && !(archive_handle->ah_flags & ARCHIVE_NUMERIC_OWNER)
-		) {
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+		if (!(archive_handle->ah_flags & ARCHIVE_NUMERIC_OWNER)) {
 			uid_t uid = file_header->uid;
 			gid_t gid = file_header->gid;
 
@@ -129,9 +128,9 @@
 				if (grp) gid = grp->gr_gid;
 			}
 			lchown(file_header->name, uid, gid);
-		} else {
+		} else
+#endif
 			lchown(file_header->name, file_header->uid, file_header->gid);
-		}
 	}
 	if ((file_header->mode & S_IFMT) != S_IFLNK) {
 		/* uclibc has no lchmod, glibc is even stranger -