mysql: disable maintainer mode

The maintainer mode enables additional gcc warnings, including
-Werror, which causes build failures with certain toolchains. Since we
generally don't enable -Werror in Buildroot, it doesn't make much
sense to have it enabled for MySQL.

Fixes:

  http://autobuild.buildroot.net/results/6b6/6b61f90d1a36ba43ff568933bb74975128380516/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/mysql/mysql.mk

@@ -30,14 +30,16 @@ MYSQL_CONF_OPT = \
 	--without-libedit \
 	--without-readline \
 	--with-low-memory \
-	--enable-thread-safe-client
+	--enable-thread-safe-client \
+	--disable-mysql-maintainer-mode
 
 ifeq ($(BR2_PACKAGE_MYSQL_SERVER),y)
 MYSQL_DEPENDENCIES += host-mysql host-bison
 HOST_MYSQL_DEPENDENCIES =
 
 HOST_MYSQL_CONF_OPT = \
-	--with-embedded-server
+	--with-embedded-server \
+	--disable-mysql-maintainer-mode
 
 MYSQL_CONF_OPT += \
 	--disable-dependency-tracking \