Slight optimization on Jenkins workspace cleanup

.ci/build.sh

@@ -223,8 +223,8 @@ EOF
 	# Clean workspace.
 	echo [-] Cleaning workspace
 	try_make clean > /dev/null
-	find . \( -name Makefile -o -name CMakeCache.txt -o -name CMakeFiles \) -exec rm -rf "{}" \; 2> /dev/null
 	rm -rf build
+	find . \( -name Makefile -o -name CMakeCache.txt -o -name CMakeFiles \) -exec rm -rf "{}" \; 2> /dev/null
 
 	# Determine available dynarec types for this architecture, and
 	# also specify ARCH right away to skip the arch_detect process.