[COMMON] Add missing ! in db_init.sh script

For some reason unknown to me I was stupid enough to forget to
put ! in a front of variable name in the final vesion of script.
Let's just quickly fix that so that not too many people notice;)

Issue-ID: OOM-2248
Change-Id: I0b8891b94856b21f4b1fad1d6731c461bae2c1aa
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
diff --git a/kubernetes/common/mariadb-init/resources/config/db_init.sh b/kubernetes/common/mariadb-init/resources/config/db_init.sh
index 8caa697..b2fdb14 100755
--- a/kubernetes/common/mariadb-init/resources/config/db_init.sh
+++ b/kubernetes/common/mariadb-init/resources/config/db_init.sh
@@ -17,8 +17,8 @@
 while read DB ; do
     USER_VAR="MYSQL_USER_${DB^^}"
     PASS_VAR="MYSQL_PASSWORD_${DB^^}"
-    USER=${USER_VAR}
-    PASS=${PASS_VAR}
+    USER=${!USER_VAR}
+    PASS=${!PASS_VAR}
     MYSQL_OPTS=( -h ${DB_HOST} -P ${DB_PORT} -uroot -p${MYSQL_ROOT_PASSWORD} )
 
     echo "Creating database ${DB} and user ${USER}..."