Fix mismatched pushd/popd on ppc64le and s390x

Executing(%check): /bin/sh -e /var/tmp/rpm-tmp.HyvLyX
+ umask 022
+ cd /builddir/build/BUILD
+ cd qemu-6.0.0
+ b=./x86_64-softmmu/qemu-system-x86_64
+ '[' -x ./x86_64-softmmu/qemu-system-x86_64 ']'
+ popd
/var/tmp/rpm-tmp.HyvLyX: line 46: popd: directory stack empty
error: Bad exit status from /var/tmp/rpm-tmp.HyvLyX (%check)

qemu.spec

@@ -1417,12 +1417,13 @@ chmod +x %{buildroot}%{_libdir}/qemu/*.so
 perl -i -p -e 's/^(127|267)/# $1/' tests/qemu-iotests/group
 %endif
 
+pushd build-dynamic
+
 # 2021-06: s390x tests randomly failing with 'Broken pipe' errors
 # dhorak couldn't reproduce locally on an s390x machine so guessed
 # it's a resource issue
 # 2021-06: ppc64le test suite hanging
 %ifnarch s390x %{power64}
-pushd build-dynamic
 make check V=1
 %endif