builddeb: Drop check for 32-bit s390

s390 now only supports 64-bit configurations.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index 389bf98..f4449b5 100755
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -21,7 +21,7 @@
 	sparc*)
 		debarch=sparc ;;
 	s390*)
-		debarch=s390$(grep -q CONFIG_64BIT=y $KCONFIG_CONFIG && echo x || true) ;;
+		debarch=s390x ;;
 	ppc*)
 		debarch=$(grep -q CPU_LITTLE_ENDIAN=y $KCONFIG_CONFIG && echo ppc64el || echo powerpc) ;;
 	parisc*)