!24 fix riscv build error

From: @mdLUbG 
Reviewed-by: @overweight 
Signed-off-by: @overweight

diffutils.spec

@@ -1,6 +1,6 @@
 Name: diffutils
 Version: 3.10
-Release: 1
+Release: 2
 Summary: A GNU collection of diff utilities
 URL: http://www.gnu.org/software/diffutils/diffutils.html
 Source: ftp://ftp.gnu.org/gnu/diffutils/diffutils-%{version}.tar.xz
@@ -28,7 +28,7 @@ GNU Diffutils is a package of several programs related to finding differences be
 autoreconf -ifv
 
 %build
-%ifarch aarch64
+%ifarch aarch64 riscv64
 CFLAGS="$RPM_OPT_FLAGS -fsigned-char"
 %endif
 %configure
@@ -56,6 +56,12 @@ cat tests/test-suite.log
 %exclude %{_infodir}/dir
 
 %changelog
+* Tue Aug 29 2023 yoo <sunyuechi@iscas.ac.cn> - 3.10-2
+- Type:bugfix
+- ID:NA
+- SUG:NA
+- DESC:fix riscv build error
+
 * Wed Jul 12 2023 dillon chen <dillon.chen@gmail.com> - 3.10-1
 - Type:enhancement
 - ID:NA