Fix hwcap test for CI

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index aec54c1..22289e5 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -4344,10 +4344,9 @@
     clang_ver="$(clang --version|grep version|sed -E 's#.*version ([0-9]+).*#\1#')"
 
     # we need asm/hwcap.h available for runtime detection
-    echo '#include <asm/hwcap.h>' | clang -E - >/dev/null 2>&1
-    have_hwcap=$?
+    echo '#include <asm/hwcap.h>' | clang -E - >/dev/null 2>&1 && no_hwcap=0 || no_hwcap=1
 
-    [[ "${clang_ver}" -ge 4 && "${have_hwcap}" -eq 0 ]]
+    [[ "${clang_ver}" -ge 4 && "${no_hwcap}" -eq 0 ]]
 }
 
 component_build_sha_armce () {