compat.sh: Skip all *ECDH_* ciphersuites

Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/tests/compat.sh b/tests/compat.sh
index ae7c682..c6653f8 100755
--- a/tests/compat.sh
+++ b/tests/compat.sh
@@ -537,9 +537,10 @@
 # o_check_ciphersuite STANDARD_CIPHER_SUITE
 o_check_ciphersuite()
 {
-    if [ "${1#*ECDH_ECDSA*}" != "$1" ] && \
-       [ "X${O_SUPPORT_ECDH}" = "XNO" ]; then
-            SKIP_NEXT="YES"
+    if [ "${O_SUPPORT_ECDH}" = "NO" ]; then
+        case "$1" in
+            *ECDH_*) SKIP_NEXT="YES"
+        esac
     fi
 }
 
@@ -614,7 +615,7 @@
 
     case $($OPENSSL ciphers ALL) in
         *ECDH-ECDSA*) O_SUPPORT_ECDH="YES";;
-        *)O_SUPPORT_ECDH="NO";;
+        *) O_SUPPORT_ECDH="NO";;
     esac
 
     if [ "X$VERIFY" = "XYES" ];