mariadb: Create compatibility symlinks

For every mysql* binary create corresponding mariadb binary and vice
versa.

Signed-off-by: Michal Hrusecky <michal.hrusecky@turris.com>

utils/mariadb/Makefile

@@ -189,9 +189,8 @@ endef
 
 define Package/mariadb/install/bin
 	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/bin/$(2) $(1)/usr/bin
-	cd "$(PKG_INSTALL_DIR)/usr/bin"; find . -maxdepth 1 -type l \
-		-regex './$(subst mysql,mariadb[-]*,$(subst _,-,$(2)))' \
-		| xargs  -I{} $(CP) {} "$(1)/usr/bin"
+	[ $(2) = $(subst mysql,mariadb,$(2)) ] || ln -s $(2) $(1)/usr/bin/$(subst mysql,mariadb,$(2))
+	[ $(2) = $(subst mariadb,mysql,$(2)) ] || ln -s $(2) $(1)/usr/bin/$(subst mariadb,mysql,$(2))
 endef
 
 define Package/mariadb/install/plugin